Method of and apparatus for making brushes

ABSTRACT

Individual bristles and/or batches of bristles are withdrawn from one or more magazines and are mechanically or pneumatically transferred to positions of alignment with the sockets of one or more forms. The individual bristles and/or batches of bristles are thereupon drawn into the aligned sockets by suction prior to being welded or glued to an adapter which constitutes or forms part of a brush body and defines the open ends of sockets during drawing of bristles into the form or forms.

BACKGROUND OF THE INVENTION

The invention relates to improvements in methods of and in apparatus formaking brushes, brooms and the like (hereinafter called brushes). Moreparticularly, the invention relates to improvements in methods of and inapparatus for making brushes containing bristles which are conveyed by agaseous fluid.

German Pat. No. 845,933 to Schiffer et al. discloses a brush makingapparatus wherein tufts of bristles are transported from a roll ofconvoluted bristles to the brush making station The making of tuftsinvolves withdrawal of bristles from the roll and introduction ofbatches of bristles into through holes which are provided in a form. Theleading ends of the bristles project beyond the respective holes so thatthey can be bonded to a brush body. The bristles are then severed at adistance from the brush body and the thus obtained free ends of bristlesare trimmed. Such trimming often involves the formation of sharp edgeswhich are likely to injure the gums of a user if the tufts are assembledwith brush bodies to form toothbrushes. The same applies if the finishedproduct is a hair brush, i.e., the sharp edges of free ends of thebristles are likely to injure or irritate the skin of the user. Thesituation is aggravated if the exposed ends or tips of the tufts are tobe trimmed for the purpose of assuming a predetermined (e.g., conical orhemispherical) configuration which enables the free ends of the bristlesto penetrate into spaces between the teeth of a user if the ultimateproduct is a toothbrush. Such shaping of the tips of tufts increases thedanger of injury or irritation because the sharp edges of all or nearlyall bristles in each tuft are free to come into contact with the gums inthe mouth or with the skin on the head of the user of a toothbrush orhairbrush employing such tufts.

Attempts to avoid the aforediscussed drawbacks of conventional brushesinvolve a treatment of the free ends of bristles, namely a treatmentwhich results in the making of rounded ends of bristles. However, suchtreatment is possible only if the tips of tufts of bristles are flat.Moreover, the treatment does not result in complete elimination of sharpedges.

Published German patent application No. 23 35 468 of Lewis discloses amethod of and an apparatus for gathering bristles into tufts which arethereupon assembled with brush bodies. The bristles consist of asynthetic material and are withdrawn from a magazine by a tool havinghollow tubular receptacles for batches of bristles. A drawback of thisapparatus is that numerous bristles are deformed as a result ofpenetration of tubular receptacles into the magazine. Misalignment ofbristles in the magazine prevents complete filling of receptacles withbristles so that the number of bristles in finished tufts departs fromthe optimum or desired number. In addition, the apparatus is rathercomplex and its output is unsatisfactory.

Published German patent application No. 34 05 001 of Bickel discloses amethod of making brushes, brooms and like products. Bristles areassembled into tufts, and the bristles of each tuft are bonded to eachother prior to being transported, by streams of compressed air, to thebrush or broom making station. The pneumatic conveyor system employsconduits which can guide finished tufts (i.e., tufts of bristles whichare already bonded to each other) but could not properly guide loosebristles. Loose bristles in a stream of compressed air or anothercompressed gaseous fluid are particularly likely to jam in arcuatesections of a conduit and at locations where they are caused to enter orleave the conduit. The making of finished tufts ahead of the pneumaticconveyor system involves losses in time and additional expenses becausethe bristles of each tuft must be welded to each other prior totransport to the brush or broom forming station where the tufts areaffixed (e.g., welded) to the bodies of brushes or brooms. Frequentinterruptions of pneumatic transport as a result of jamming of conveyedtufts also affects the output of the apparatus.

Published German patent application No. 28 08 966 of Lorenz discloses abrush making apparatus wherein the bristles are transported exclusivelyby mechanical means. The apparatus comprises means for maintainingbristles in vertical positions and employs an ejector for finishedbrushes.

U.S Pat. No. 3,230,015 to Iasillo discloses a brush making machinewherein the bristles are drawn from a magazine and are thereuponmanipulated by mechanical means. The device which draws bristles fromthe magazine has recesses for bunches of bristles.

The apparatus which is disclosed in published German patent applicationNo. 1 632 375 of Neubauer et al. also employs a tool having recesses forbatches of bristles which are drawn from the bottom end of an uprightmagazine.

Published German patent application No. 36 16 976 of Blankscheindiscloses a form with sockets for batches of bristles. The shape of thebottom wall in each socket determines the configuration of the tip ofthe respective tuft.

German Pat. No. 27 31 762 to Zahoransky discloses a brush makingapparatus wherein brushes are assembled in a number of successivestages. Each of those stations where the treatment of partially finishedbrushes or component parts of brushes takes up relatively long intervalsof time is designed to accept two identical partly finished brushes ortwo identical component parts of brushes. The bristles are transportedexclusively by mechanical means, the same as in each of theaforediscussed prior publications save for the published application ofBickel.

German Utility Model No. 1 769 825 of Greiner & Hausser discloseswelding of bristles in batches of bristles to each other prior topartial insertion of the thus obtained tufts into and their welding tothe body of a toothbrush. Portions of tufts can be inserted into blindbores or holes of the brush body, or are caused to extend all the waythrough the brush body to be secured to the latter by welding or by theapplication of a layer of hardenable material.

Published German patent application No. 25 39 417 of Hersche discloses abrush with replaceable bristles. To this end, batches of bristles areinserted into the through holes of a form which is located between apusher plate and a heating plate. The pusher plate bears against thefirst ends of bristles and forces the second ends of such bristlesagainst the heating plate which causes the adjacent portions of thebristles to melt. Molten material of the bristles is gathered into athin substrate which is integral with the bristles of all batches sothat the batches form tufts of bristles. The substrate can be secured tothe periphery of a drum or to another holder of tufts. If the tufts aredamaged or destroyed, the substrate is removed from the holder and isreplaced with a substrate carrying a requisite number of fresh tufts.The substrate and its tufts are intended for use in plants or machineswherein the bristles are subjected to extensive wear and wherein it paysto replace the bristles while retaining all other parts of a cleaning,brushing, smoothing or like machine.

OBJECTS OF THE INVENTION

An object of the invention is to provide a novel and improved method ofgathering bristles into arrays which are ready to be anchored in thebodies of brushes.

Another object of the invention is to provide a simple and economicalmethod of arraying bristles preparatory to attachment of bristles to thebodies of brushes.

A further object of the invention is to provide a novel and improvedmethod of anchoring bristles in the bodies of brushes.

An additional object of the invention is to provide a novel and improvedmethod of drawing bristles from one or more sources and a novel andimproved method of conveying the thus withdrawn bristles to the brushforming or assembling station or stations.

Still another object of the invention is to provide a method whichrenders it possible to accumulate any desired arrays of bristles andtufts of bristles within short periods of time and which renders itpossible to dispense with the trimming of tufts of bristles in afinished brush.

A further object of the invention is to provide a novel and improvedmethod of making paintbrushes, such as artists' brushes.

Another object of the invention is to provide a novel and improvedapparatus for the practice of the above outlined method.

An additional object of the invention is to provide a novel and improvedsource of bristles for use in the above outlined apparatus.

Another object of the invention is to provide novel and improved meansfor conveying bristles and tufts of bristles in the above outlinedapparatus.

Still another object of the invention is to provide novel and improvedforms for use in the above outlined apparatus.

A further object of the invention is to provide the apparatus with noveland improved means for imparting to the exposed ends of tufts ofbristles a desired configuration in the course of the brush makingoperation.

Another object of the invention is to provide novel and improved brushbodies for assembly with bristles in the above outlined apparatus.

An additional object of the invention is to provide an apparatus whichcan assemble large quantities of simple or complex brushes per unit oftime.

Another object of the invention is to provide the apparatus with noveland improved means for preventing misorientation and/or jamming ofbristles on their way from the source of bristles to the brushassembling station or stations.

A further object of the invention is to provide a novel and improvedapparatus for the making of toothbrushes.

Another object of the invention is to provide an apparatus which isconstructed and assembled in such a way that its constituents can beinstalled at several spaced-apart locations to take advantage of thespace which happens to be available in a bristle making and brush makingplant.

An additional object of the invention is to provide an apparatus whichis capable of reliably securing bristles and tufts of bristles to brushbodies in a simple and inexpensive way and at a frequency greatlyexceeding the frequency at which brushes are assembled in conventionalapparatus.

Another object of the invention is to provide an apparatus wherein thebristles of tufts of bristles need not be fixed to each other ahead ofthe brush assembling station or stations.

A further object of the invention is to provide an apparatus which cansimultaneously produce two or more brushes and which can assemblebrushes with bristles having identical or different colors, diameters,flexibilities and/or other characteristics.

SUMMARY OF THE INVENTION

One feature of the present invention resides in the provision of amethod of making brushes from bristles (particularly thermoplasticbristles) in at least one form which is permeable to gaseous fluids andhas at least one array of bristle-receiving open-ended sockets. Themethod comprises the steps of establishing and maintaining at least onesupply of bristles (e.g., one or more magazines for large quantities ofparallel bristles), conveying predetermined numbers of bristles from theat least one supply to the sockets of the at least one form includingdrawing air from the sockets through the permeable form so that thebristles are introduced into the sockets by suction and portions of thethus introduced bristles are located at the open ends of the respectivesockets, and enlarging the portions of the bristles at the open ends ofthe respective sockets. The enlarging step can include heating theportions of properly introduced bristles at least close to the meltingpoint of their thermoplastic material.

Each predetermined number of bristles can include a single bristle or atuft of two or more at least substantially parallel bristles Theconveying step can further comprise establishing discrete at leastsubstantially sealed paths for the single bristles or for the tufts ofbristles, and each such path extends from the at least one source to therespective sockets. The aforementioned drawing step then preferablyincludes drawing from the sockets air at such a rate that the drawing ofair from the sockets entails the advancement of single bristles or tuftsof bristles along the respective paths and into the respective sockets.

The conveying step can comprise (and preferably comprises) introducingthe bristles into the respective sockets by moving the bristlessubstantially vertically downwardly so that the aforementioned portionsof the bristles constitute the trailing upper end portions of therespective bristles.

The brushes can be made in and/or at least one form which has a mainsection with major parts of the sockets and a preferably detachablecover which overlaps the main section and has neighboring aperturesconstituting the open ends of the sockets in the form. Theaforementioned portions of properly introduced bristles are confined inor extend outwardly beyond the respective apertures of the cover. Theenlarging step can include bonding (e.g., welding or adhesivelysecuring) portions of the bristles to the cover, bonding portions ofbristles in neighboring apertures of the cover to each other, or bondingportions of two or more bristles in a properly introduced tuft to eachother and/or to the cover and/or to portions of bristles forming tuftsin neighboring sockets of the form.

The cover can be provided with at least one protuberance adjacent eachof its apertures, and the enlarging step can include bonding portions ofproperly introduced bristles to the adjacent protuberances of the cover.

Each aperture of the cover can include a portion which is remote fromthe main section of the form and diverges in a direction away from themain section. The enlarging step can include heating portions ofintroduced bristles in the enlarged portions of the respectiveapertures. The portions of bristles in or at the enlarged portions ofthe respective apertures can be heated at least close to the meltingpoint of thermoplastic material of the bristles in order to soften suchportions of the bristles, and the enlarging step or a separate stepwhich follows the enlarging step can include at least partially forcingthe softened portions of bristles into the respective apertures of thecover. Such forcing step can include drawing the softened portions ofbristles into the respective apertures by suction. If each socketreceives a tuft of bristles, the forcing step can include or can entailbonding softened portions of the bristles in each tuft to each otherand/or to the cover.

The cover is subsequently separated from the main section of the form,and the method can further comprise the step of securing the separatedcover and the bristles to a brush body; such securing step can includemechanically fastening (e.g., by screws or the like or by a force fit)the separated cover to a brush body, welding (e.g., with ahigh-frequency welding apparatus) the separated cover to a brush body orbonding the separated cover to a brush body by resorting to a suitableadhesive. It is also possible to impart to the cover the shape of abrush body, either prior to attachment of the cover to the main portionof the form or subsequent to separation of the cover (with bristles)from the main section of the form.

Another feature of the invention resides in the provision of anapparatus for making brushes from bristles, particularly fromthermoplastic bristles. The improved apparatus comprises at least onesource of bristles, an assembling unit including at least one permeableform having bristle-receiving open-ended sockets or pockets, means forconveying predetermined numbers of bristles from the at least one sourceto the sockets including means for drawing air from the sockets throughthe permeable form so that the bristles are introduced into the socketsby suction and portions of the thus introduced bristles are located atthe open ends of the respective sockets, and means for enlarging theaforementioned portions of introduced bristles at the open ends of therespective sockets.

The conveying means can further comprise a conduit for eachpredetermined number of bristles, i.e., one for each socket. Theconduits have receiving ends at the at least one source and dischargeends at the open ends of the respective sockets. The means for drawingair then preferably includes means for advancing bristles by suctionfrom the receiving ends toward and beyond the discharge ends of theconduits, i.e., into the respective sockets. The apparatus furthercomprises means for effecting a relative movement between the dischargeends of the conduits and the form, i.e., for moving the form relative tothe discharge ends of the conduits and/or vice versa.

If the bristles are made of a thermoplastic material, the enlargingmeans preferably includes means for heating the aforementioned portionsof properly introduced bristles at least close to the melting point oftheir thermoplastic material.

The at least one source and/or the conveying means can include means formaintaining the predetermined numbers of bristles in a firstpredetermined distribution, and the distribution of receiving ends ofthe conduits preferably matches such first distribution so that eachreceiving end is in a position to receive one of the predeterminednumbers of bristles. Analogously, the sockets can be maintained in asecond predetermined distribution which may but beed not match the firstdistribution, and the distribution of discharge ends of the conduitsmatches the second distribution so that each discharge end can admit oneof the predetermined numbers of bristles into a discrete socket of theform.

Each conduit is or can be flexible, at least in the region of itsreceiving and/or discharging end. For example, each conduit canconstitute or include a flexible hose having an inner diameter within arange of 0.1 to 20 mm, depending on the diameters and/or upon the numberof bristles in the respective predetermined number.

The conveying means can further comprise a carrier (e.g., a plate- orstrip-shaped support) for the receiving ends of the conduits. Suchcarrier can be provided with passages for the predetermined numbers ofbristles, and each passage communicates with and preferably convergestoward the receiving end of a discrete conduit. Each passage can have aminimum diameter which equals or approximates the inner diameter of therespective conduit.

The conveying means can further comprise a carrier or support (e.g., aplate or a strip) for the discharge ends of the conduits.

The discharge ends of the conduits can include or constitute or bealigned with flow restrictors; for example, each flow restrictor canconstitute a venturi which causes an acceleration of air flowing fromthe conduit into the registering socket and an acceleration of thebristle or bristles in the conduit.

The source can comprise a plurality of magazines for accumulations ofpreferably parallel bristles, and means for transferring predeterminednumbers of bristles from the magazines to the receiving ends of theconduits.

The assembling unit can comprise a plurality of forms, and the apparatuscan comprise means (e.g., an endless belt or chain conveyor) fortransporting the plurality of forms in a predetermined direction along apredetermined path having a first portion or station adjacent thedischarge ends of the conduits and a second portion or station adjacentthe enlarging means. The second portion of the path is locateddownstream of the first portion, and the path can have a third portionor station which is located downstream of the second portion and isadjacent a means for delivering suitable brush bodies from a source ofbrush bodies to successive forms reaching the third portion of the path.The third portion or a further portion or station of the path can beadjacent a means for treating the bristles in successive forms, e.g.,for welding separable covers of successive forms (with the insertedbristles) to discrete brush bodies.

The arrangement may be such that the transporting means for the formsincludes a first reach or stretch which defines at least the first andsecond portions or stations of the path, and a second reach or stretchwhich defines an additional portion or station of the path downstream ofthe aforediscussed (first and second or first, second and third)portions. Such apparatus can further comprise an ejector or othersuitable means for segregating brushes the predetermined numbers ofbristles from the respective forms in the additional portion of thepath.

As mentioned above, each form can include a cover, and such form furtherincludes a main section which overlaps the cover and is provided withblind holes or bores constituting portions of the sockets. The cover hasapertures which register with the blind bores or holes and constitutethe open ends of the respective sockets. The aforementioned portions ofproperly introduced bristles are located at the respective apertures ofthe cover. The apertures can include portions which are spaced apartfrom and diverge in a direction away from the main section of the form.Each aperture can communicate with at least one other aperture of thecover.

The source can comprise at least one magazine, and the apparatus canfurther comprise means for accumulating the predetermined numbers ofbristles. Such accumulating means can include at least one transfermember with bristle-receiving pockets and means for moving the transfermember between at least one first position in which at least some of thepockets receive bristles from the at least one magazine and at least onesecond position in which the bristle-containing pockets are locatedexternally of the magazine, e.g., in positions of register with thereceiving ends of the aforementioned conduits or in register with theopen ends of sockets in a form.

The sockets can include or constitute blind holes or bores, and the formcan be provided with profiled (flat, concave, convex, undulate, slopingor conical) bottom surfaces in the blind holes to intercept and arrestthe introduced bristles in predetermined axial positions with referenceto the form.

The drawing means can comprise at least one suction port or channelprovided in the form for each socket and extending substantiallylaterally of and communicating with the respective socket, and means(e.g., a suction chamber in the form) for evacuating air from thechannels. The intake ends of the channels communicate with therespective sockets, and the discharge ends of the channels communicatewith the suction chamber.

The form can include at least one foraminous insert which is adjacentand can define portions of the sockets, and the drawing means thencomprises means for evacuating air from the sockets through the at leastone foraminous insert. The evacuating means can include a suctionchamber which is or can be provided in the form adjacent the at leastone insert.

Each socket can form part of a discrete cylinder chamber in the form,and such form can further comprise a piston extending into each cylinderchamber and constituting an abutment for bristles which are introducedinto the respective socket. This form can further comprise means formoving the pistons in the respective cylinder chambers to thus vary theeffective depth of the sockets and to select the positions of theaforementioned portions of introduced bristles with reference to openends of the respective sockets. For example, the pistons can be causedto shift the trailing ends of the bristles outwardly preparatory towelding of such trailing ends of the bristles to neighboring trailingends or to a cover.

At least one bottom surface in the form can be provided with at leastone hill and at least one valley so that, when a batch or tuft ofbristles is introduced into the respective socket, some of the bristlesare arrested or intercepted by the raised (hilly) portion and the otherbristles are intercepted by the valleyed portion of the bottom surfaceto thus impart to the tufts in the finished product a predeterminedshape (e.g., the tips of bristles in a toothbrush need not be located ina common plane but instead form a complex profile including hills andvalleys. This can hold true for each tuft or for selected tufts ofbristles in a finished brush. Staggering of those ends of bristles whichpenetrate into the deepmost portions of the respective sockets isdesirable in connection with the making of many types of brushesincluding toothbrushes, paintbrushes and others.

The assembling unit of the improved apparatus can comprise at least twoforms each of which has a plurality of sockets, and such apparatus cancomprise conduits which define discrete paths for simultaneous deliveryof bristles from the source to the sockets of several forms.

The conveying means can further comprise means for receiving bristlesfrom the source, for gathering the thus received bristles into tuftscontaining different numbers of bristles, and for delivering the tuftsto the sockets.

The source can comprise a plurality of magazines and means forsimultaneously withdrawing tufts of bristles from the magazines. Suchsource can include a first and a second magazine, and the withdrawingmeans of the apparatus can comprise a transfer member which is disposedbetween the first and second magazines and has first and second sidesadjacent the first and second magazines, respectively. Each side of thetransfer member has at least one bristle-receiving pocket, and suchapparatus can further comprise means for moving the transfer memberbetween at least one first position in which the pockets receivebristles from the respective magazines and at least one second positionin which the bristle-containing pockets are spaced apart from themagazines.

Each form can include a main section and a cover which overlaps and isseparable from the main section. The sockets include portions (normallyin the form of blind holes or bores) in the main section, and the coverhas apertures which constitute the open ends of the sockets in assembledcondition of the form. The cover of each form can be provided with aflange or lip which overlies and surrounds a recess of a brush body.Alternatively, the cover can be provided with a recess to receive aflange or another projection or protuberance of the brush body.

The cover for each form can be made of a material which is the materialof a brush body so that the brush is completed when the bristles arewelded or otherwise secured to the cover and the latter is separatedfrom the main section of the respective form.

The conveying means can further comprise means for mechanicallyadvancing predetermined numbers of bristles from the source to thesockets; such means for mechanically advancing can replace theaforediscussed conduits. The advancing means can include a transfermember and means for moving the transfer member between at least onefirst position in which the transfer member receives bristles from thesource and at least one second position in which the thus receivedbristles are aligned with the sockets of a single form or with thesockets of two or more forms. Such apparatus can further comprise guidemeans having openings in register with the open ends of the sockets, atleast in the at least one second position of the transfer member, andthe guide means is then disposed between the open ends of the socketsand the transfer member in the at least one second position of thetransfer member so that the drawing means can introduce bristles intothe sockets through the openings of the guide means.

As mentioned above, each form can have at least one foraminous insertwhich is adjacent the respective sockets, and the drawing means of anapparatus employing such form or forms includes means for evacuating airfrom the sockets through the at least one insert.

The cover of a composite form can be provided with thermoplasticprojections which are adjacent its apertures, and the enlarging means ofsuch apparatus can include means for bonding (e.g., welding) theaforementioned portions of the bristles to the adjacent projections ofthe cover.

The source of bristles can comprise at least one magazine, and theapparatus can further comprise an indexible transfer member havingbristle-receiving pockets and means for indexing the transfer member(preferably about a substantially vertical axis) between at least onefirst position in which at least some of the pockets receive bristlesfrom the at least one magazine, and at least one second position inwhich the bristle-containing pockets are spaced apart from the at leastone magazine. The source can contain a plurality of magazines and thepockets then preferably form sets of pockets (particularly two sets ofpockets for each magazine). The transfer member is preferably indexiblein a single direction between a plurality of first and second positionsin each of which several pockets receive bristles from the pluralmagazines and several sets of pockets (which contain bristles) arespaced apart from the magazines.

The transfer member is or can be indexible through angles ofapproximately 90° if the source of bristles comprises two magazineswhich are disposed diametrically or substantially diametrically oppositeeach other with reference to the indexible transfer member.

The transfer member can include or constitute a rotary disc having acylindrical or substantially cylindrical peripheral surface with axiallyparallel open recesses which constitute the aforementioned pockets.

The arrangement may be such that the bristle-containing pockets registerwith the sockets of at least one form in the at least one secondposition of the indexible transfer member, or that the conveying meansfurther comprises conduits which establish paths for advancement ofbristles from bristle-containing pockets of the indexible transfermember to the sockets of one or more forms in the at least one secondposition of the transfer member.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved apparatus itself, however, both as to its construction and itsmode of operation, together with additional features and advantagesthereof, will be best understood upon perusal of the following detaileddescription of certain presently preferred specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic partly elevational and partly vertical sectionalview of a first apparatus which embodies the invention and wherein theforms have foraminous inserts defining portions of sockets for discretebristles or tufts of bristles;

FIG. 1a is a fragmentary sectional view of a modified form which doesnot embody a foraminous insert;

FIG. 1b is a fragmentary sectional view of another form wherein theeffective length of the sockets can be varied by discrete pistons;

FIG. 2 is a plan view of a source of bristles which can be utilized inthe apparatus of FIG. 1 and wherein a single transfer member serves towithdraw bristles from two discrete magazines;

FIG. 3 is a plan view of a form with an oval array of sockets fordiscrete bristles and/or tufts of bristles;

FIG. 4 is a partly elevational and partly vertical sectional view of amodified apparatus with a larger number of conduits between the sourceof bristles and the station where the bristles are introduced into thesockets of successive forms, and further showing the means for deformingthe end portions of introduced bristles and the means for assemblinginserted bristles and covers with brush bodies;

FIG. 5 is a fragmentary sectional view of a form with a modified coverand of four tufts which are not bonded to each other;

FIG. 6 is a view similar to that of FIG. 5 but showing a modified coverwherein the deformed end portions of bristles in neighboring sockets ofthe form are bonded to each other;

FIG. 7 is a plan view of the cover which is shown in FIG. 6;

FIG. 8 is a side elevational view of a brush body and a sectional viewof a cover with a set of tufts and with a flange, or lip serving tooverlie and seal a recess in the rush body;

FIG. 9 is a partly side elevational and partly sectional view of atoothbrush wherein the cover forms an integral part of the brush body, aplate-like lid being shown adjacent a recess in the rear side of thebrush body behind the deformed end portions of bristles in the cover;

FIG. 10 is a fragmentary partly elevational and partly sectional view ofa brush wherein the tufts of bristles are anchored, in the cover in amanner as shown in FIG. 6 and the tufts include shorter and longertufts;

FIG. 11 is a view substantially as seen in the direction of arrows fromthe line XI--XI of FIG. 10;

FIG. 11a is a fragmentary sectional view of a form for the making ofbrushes of the type shown in FIG. 10;

FIG. 12 is an enlarged view of a tuft of the type shown in FIG. 11;

FIG. 13 is a plan view of a tuft;

FIG. 14 is a partly elevational and partly vertical sectional view of anapparatus which constitutes a further modification of the apparatus ofFIG. 1 and wherein the support for the discharge ends ofbristle-conveying conduits is provided with flow restrictors serving toaccelerate bristles on their way into the registering sockets;

FIG. 15 is a partly elevational and partly vertical sectional view of afurther apparatus wherein bristles and/or tufts of bristles aremechanically conveyed from the source of bristles to positions ofalignment with the sockets of a form; and

FIG. 16 is a plan view of a modified source of bristles wherein thetransfer member is indexible to simultaneously withdraw sets of bristlesand/or tufts from several magazines for delivery into alignment withconduits or directly with the sockets of several forms wherein thebristles are deformed and thereupon secured to brush bodies.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1, 2 and 4 show certain details of a brush making apparatus 1which can be used to assemble arrays 2 (see, for example, FIGS. 8 and 9)of individual bristles 4 or tufts 5 of bristles 4 with brush bodies(such as the brush body 26 of FIG. 8) into finished articles in the formof toothbrushes (FIGS. 8 and 9), paintbrushes (including those to beused by artists and those used by house painters or other artisans)and/or other setaceous products. The making of brushes involvesdeforming (hereinafter simply called enlarging) one end of each bristle4 into reliable engagement with one or more adjacent bristles and/orwith the adjacent portion of a cover or adapter (shown at 14 in FIG. 1).If the brush contains tufts 5 of bristles 4 (rather than arrays ofindividual bristles), the anchored ends of bristles 4 in each tuft 5 canbe welded, glued or otherwise reliably secured to other bristles of therespective tuft and/or to the bristles of one or more neighboring tuftsand/or to the brush body. The presently preferred mode of enlarging theanchored end portions or ends 8 of bristles 4 is to heat thermoplasticbristles at least close to the melting point of their material and tothereupon deform as well as anchor the heated and softened ends 8 ofbristles in the brush body.

The apparatus 1 comprises one or more forms 7 each of which includes amain section 7a and a plate-like cover 14 which overlaps the respectivemain section 7a. The form 7 has sockets 6 which, in turn, have blindbores or holes 6c in the main section 7a and open ends constituted byapertures 6a in the cover 14. When a cover or adapter 14 is properly(but separably) connected or coupled to the respective main section 7a,each of its apertures 6a registers with the open end of a blind hole 6cin the adjacent main section so that the thus formed composite socket 6is ready to receive a discrete bristle 4 or a tuft 5 of two or more atleast substantially parallel bristles 4. As can be seen in FIG. 1, whichshows a single form 7 and a tuft 5 of bristles 4 in one of severalsockets 6, the exposed end portions or ends 8 of the bristles 4 arelocated at the upwardly diverging portion 6b of the respective aperture6a, namely at that end of the aperture which is remote from the mainsection 7a of the form 7. The end portions 8 are thereupon welded toeach other and/or to the adjacent portion of the cover 14 and/or to theend portions 8 of bristles 4 forming a tuft 5 (not shown) in one or moreadjacent sockets 6. The end portions 8 which are to be enlarged (e.g.,welded) can project slightly beyond the exposed upper side of the cover14 or they can be confined in the enlarged portion 6b of the respectiveaperture 6a, depending upon the desired anchoring force and/or upon thenature of connection to be established between the bristles 4 and thecover 14.

The main section 7a of each form 7 has an air evacuating portion 9 inthe form of a nipple which is connected to a suction generating device(such as a vacuum pump P shown in FIG. 1a) serving to evacuate air froma suction chamber 23 in the main section 7a. The latter contains aforaminous insert 22 one side of which is adjacent the suction chamber23 and another side of which is formed with relatively shallow recessesconstituting the deepmost portions of the blind holes or bores 6c in themain section 7a of the form 7. Thus, the insert 22 defines the bottomsurfaces 21 in the sockets 6, and the profiles of such bottom surfacesdetermine the axial positions of bristles 4 in the respective tufts 5.FIG. 1 shows, by way of example, that one of the sockets 6 can bebounded by a concave bottom surface 21, that another socket 6 can bebounded by a flat bottom surface 21, and that a third socket 6 can bebounded by a conical bottom surface 21. One or more bottom surfaces 21can be inclined relative to the recessed side of the insert 22, and itis equally possible to provide the insert with convex, partly flat andpartly concave and/or otherwise configurated bottom surfaces for therespective sockets 6. The profiles of all bottom surfaces 21 in aninsert 22 may but need not be the same. Furthermore, the insert 22 canconsist of two or more parts which are fitted together in the internalspace of the main section 7a to define the deepmost portions of thesockets 6 and to impart a desired shape to the adjacent end faces oftufts 5 in the respective sockets.

The means for conveying discrete bristles 4 or tufts 5 of bristles 4from a source of such bristles toward and into the sockets 6 includes aplurality of conduits 10, one for each socket 6 of a single form 7 orone for each socket of two or more forms, depending upon the capacity ofthe brush making apparatus. Such conveying means further includes thesuction chamber or chambers 23 and the nipple(s) 9 as well as thesuction generating device P which cooperates with the suction chamber(s)and with the nipple(s) to draw discrete bristles 4 or tufts 5 ofsubstantially parallel bristles by suction all the way from the sourceinto the respective sockets 6. The inner diameter of each conduit 10 canbe in the range of 0.1 to 20 mm, depending upon the diameters ofdiscrete bristles 4 and upon the transverse dimensions of the tufts 5.As a rule, the inner diameter of a conduit 10 will slightly exceed thediameter of a discrete bristle or the diameter of a tuft which is to bedrawn into the respective socket 6. The conduits 10 define at leastsubstantially sealed paths for advancement of discrete bristles 4 and/ortufts 5 of bristles.

The discharge ends 12a of the conduits 10 are affixed to or extend intoa plate- or strip-shaped carrier or support 20 which is movable relativeto the form 7 (and/or vice versa) in directions indicated by adouble-headed arrow Pf1. The support 20 has passages 11 (e.g., in theform of cylindrical bores or holes) which register with the dischargeends 12a of the conduits 10 and with the open ends 6b of the sockets 6in a form 7 which is ready to receive a predetermined number of bristles4 in the form of tufts 5 and/or individual bristles, depending upon thenature of the ultimate product.

The movability of the support 20 and form 7 relative to each other neednot be only in the axial direction (arrow Pf1) of the sockets 6 but alsoin one or more other directions. For example, the support 20 can bemounted for movement in directions which are indicated by thedouble-headed arrow Pf1, and the form or forms 7 can be mounted formovement in the direction of arrow Pf2 shown in FIG. 4.

The apparatus 1 can be furnished with two or more different supports 20,one for each of two or more different arrays 2 of tufts 5 in a brush 3which is to be produced in the improved apparatus 1. Thus, the dischargeends 12a of the conduits 10 can be detached from the illustrated support20 to be separably connectable with at least one additional supporthaving a different distribution of passages 11, depending on thedistribution of sockets 6 in a form 7 which is to receive bristles 4through the passages of the support which is to replace the support 20of FIG. 1. At least the discharge ends 12a of the conduits 10 areflexible to permit a desired distribution of such discharge ends,depending upon the distribution of passages 11 in a selected support 20.For example, a portion of each conduit 10, or each of these conduits,can constitute a flexible hole which can be made (at least in part) oflight-transmitting material to permit convenient observation ofadvancement of bristles 4 or tufts 5 of bristles from the source towardand into the respective sockets 6.

The bristle-receiving ends 12 of the conduits 10 are separably orpermanently connected to a plate- or strip-shaped carrier or support 13which has passages 19 for admission of bristles or tufts of bristlesinto the respective conduits. The passages 19 have downwardly divergingfrustoconical portions which facilitate penetration of discrete bristlesor tufts of bristles into the respective conduits 10. The distributionof passages 19 in the carrier 13 may but need not be the same as thedistribution of passages 11 in the support 20. The carrier 13 is movablein directions which are indicated by a double-headed arrow 13A, e.g., bya fluid-operated (pneumatic or hydraulic) motor, not shown.

The bristle-receiving ends 12 of the conduits 10 are or can be separablysecured to the carrier 13, depending upon whether the apparatus 1 isfurnished with a single carrier or with two or more carriers. If thedistribution of receiving ends 12 is to be changed, those portions ofthe conduits 10 which include the receiving ends 12 are made of aflexible material. Alternatively, and as already mentioned above, eachconduit 10 can constitute a flexible hose.

It goes without saying that the support 20 is at least closely adjacentbut preferably sealingly engages the exposed side of the cover 14 toprevent the flow of excessive quantities of atmospheric air between theparts 14, 20 and into the sockets 6 when the suction generating device Pis on to draw bristles 4 from the receiving ends 12 of the conduits 10into and beyond the respective discharge ends 12a, i.e., into theregistering sockets 6 of the form 7 which abuts or is adjacent thesupport 20.

The source of bristles 4 can comprise one or more magazines 15 each ofwhich can receive and confine a rather large supply of preferablyparallel and preferably vertical or nearly vertical bristles. FIG. 2shows a source with two mirror symmetrical magazines 15 and a transfermember 17 between the two magazines. Magazines which can be used in theapparatus of the present invention are described, for example, in U.S.Pats. Nos. 4,647,113, 4,610,481 and 4,904,025 to which reference may behad, if necessary.

The transfer member 17 has two parallel sides 16 which close theadjacent openings of the magazines 15 and are provided with groups ofpockets 18 for reception of individual bristles 4 or of tufts 5 ofbristles from the respective magazines 15. To this end, the supplies ofbristles 4 in the magazines 15 are urged against the respective sides 16of the transfer member 17 by pushers 15a acting in directions which areindicated by arrows Pf3. A motor 17a (e.g., a double-acting cylinder andpiston unit) is provided to move the transfer member 17 between at leastone first position in which one or more pockets 18 in the right-handside 16 of the transfer member can receive bristles 4 from theright-hand magazine 15 of FIG. 2 and one or more pockets 18 in theleft-hand side 16 of the transfer member 17 can receive bristles 4 fromthe left-hand magazine 15, and at least one second position in which thebristle-containing (filled) pockets 18 are spaced apart from themagazines 15 to assume positions in which their contents can enter theadjacent receiving ends 12 of the conduits 10 for advancement into thecorresponding sockets 6. The directions in which the transfer member 17is movable (preferably reciprocable) between its first and secondpositions are indicated by a double-headed arrow 17A.

The source which is shown in FIG. 2 further comprises two walls 18awhich are pressed against the adjacent sides 16 of the transfer member17 by double-acting cylinder and piston units 18b or by other suitablebiasing means which enable the walls 18a to prevent escape of bristles 4and/or tufts 5 from the pockets 18 during transfer of such bristles ortufts from the respective magazines 15 to positions of alignment withthe respective receiving ends 12.

The pockets 18 in the right-hand side 16 of the transfer member 17 ofFIG. 2 may but need not be identical with the pockets 18 in theleft-hand side 16. Furthermore, the one and/or the other side 16 of thetransfer member 17 can be provided with differently configurated pockets18 which can receive different numbers and different arrays of bristles4. This can be readily seen in FIG. 2 wherein each of the two sides 16is formed with larger and smaller pockets 18. FIG. 1 shows the transfermember 17 in the second position in which some of its pockets 18maintain tufts 5 of bristles 4 a predetermined distribution, namely inpositions of register with the adjacent receiving ends 12 of therespective conduits 10. One of the magazines 15 can be emptied if thepockets 18 in one side 16 of the transfer member 17 suffice to supplytufts 5 to the receiving ends 12 of all conduits 10 which are to advancesuch tufts into the registering sockets 6 of the form 7 which is thenadjacent the support 20.

If the apparatus 1 is set up for the making of a single type of brushes3, the conduits 10 can be made of a metallic or rigid plastic materialbecause it is not necessary to change the distribution of the receivingends 12 and/or discharge ends 12a. The utilization of a carrier 13 withdownwardly diverging frustoconical or partly frustoconical passages 19is particularly desirable if the conduits 10 are to receive tufts 5 ofparallel bristles 4; the surfaces surrounding such passages 19facilitate unimpeded or practically unimpeded entry of all bristles 4 ofeach tuft 5 into the respective conduit 10.

The provision of bottom surfaces 21 having a predetermined profile isparticularly advantageous when the exposed ends of the tufts 5 in afinished brush 3 (the exposed ends are those ends which are received inthe recesses of the insert 21 upon completed conveying of tufts from thetransfer member 17 into the respective sockets 6) are to exhibit aparticular shape (e.g., a conical shape, a hemispherical shape or a morecomplex shape). Thus, it is not necessary to trim the tips of tufts 5 ina finished brush 3 because the tips of such tufts can be imparted aparticular profile as a result of conveying them by suction into thesockets 6 and into abutment with the respective bottom surfaces 21 inthe recesses of the insert 22.

FIG. 1a shows a modified form 107 which need not contain or comprise aforaminous insert because its sockets 106 communicate with the suctionchamber 123 by way of suction ports or channels 123a. The intake ends ofthe channels 123a extend substantially radially and laterally of therespective sockets 106, and the discharge ends of these channelscommunicate with the suction chamber 123. The latter is connected withthe suction generating device P by a nipple 109 and/or in any othersuitable way. A conduit C between the nipple 109 and the suctiongenerating device P contains a shutoff valve V. The form 107 of FIG. 1acan also include a main section and a cover 114 which latter hasapertures constituting the open ends of the sockets 106. Each of thesesockets can be communicatively connected with the suction chamber 123 bytwo or more channels or ports 123a. The positions of intake ends of thechannels 123a are selected with a view to ensure that each bristle ineach of the sockets 106 actually reaches and abuts the bottom surface121. It is further possible to connect the discharge ends of two or morechannels 123a with a larger channel or bore which serves to conveyevacuated air into the suction chamber 123.

The insert 22 of FIG. 1 can be made of a sintered metallic or ceramicmaterial which exhibits a required porosity to permit predictableevacuation of air from the sockets 6 when the suction generating deviceP is on to draw discrete bristles 4 or tufts 5 of bristles 4 toward andinto abutment with the bottom surfaces 21 in the respective sockets 6.The insert 22 can also be made of a textile material (e.g., felt) or anyother material which exhibits satisfactory permeability for the purposeof enabling the suction generating device P to draw tufts of bristles 4all the way from the transfer member 17 (via conduits 10) and into thesockets 6. An advantage of a form 7 with a foraminous insert 22 over aform 107 of the type shown in FIG. 1a is that the leading ends ofbristles 4 are more likely to advance all the way into abutment with therespective bottom surfaces 21. On the other hand, the form 107 exhibitsthe advantage that the channels 123a in its main section are less likelyto be rapidly clogged than the pores of the insert 22.

The insert 22 can be replaced with a simple filter or screen havinginterstices which are sufficiently large to permit rapid evacuation ofair from the sockets 6 but still enable the filter or screen toinvariably intercept the front ends of bristles 4, i.e., the bottomsurfaces 21 of the insert or filter must invariably intercept thebristles 4 in desired axial positions in which the tips of tufts 5 inthe sockets 6 exhibit a desired (conical, hemispherical, flat or a morecomplex) configuration.

FIG. 10 shows that the distribution and/or length of bristles 4 in eachtuft 5 of a finished brush 3 (e.g., a toothbrush) need not be the same.Thus, each tuft 5 can consist of shorter and longer bristles 4, and thedimensions of some or all of the tufts 5 in a brush 3 can be different.More specifically, FIG. 10 shows that certain tufts 5 can havesubstantially hemispherical tips (i.e., free ends bounded bysubstantially convex surfaces) and that certain other tufts 5 can havetips with alternating hills and valleys.

FIG. 11 shows that all of the tufts 5 are identical but that each ofthese tufts consists of shorter and longer bristles 4. Brushes 3 of thetype shown in FIGS. 10 and 11 are preferred for numerous applicationsbecause the cleaning effect of their bristles 4 is more satisfactory ifthe effective length of all bristles in a tuft 5 and/or of all bristlesin the brush is not the same. The configurations of the free ends ortips of tufts 5 which are shown in FIGS. 10 and 11 can be arrived at bythe simple expedient of properly selecting the profiles of bottomsurfaces 21 in the sockets 6 of the form 7 or 107 in which bristles areassembled to form tufts of the type shown in FIGS. 10 and 11. FIG. 11ashows a portion of a form 7 with a socket 6 wherein the bottom surface21 has a set of alternating hills and valleys for the purpose ofassembling tufts 5 of the type shown in FIG. 11. A single tuft 5 of thetype shown in FIG. 11 is shown on a larger scale in FIG. 12. FIG. 13shows that a tuft 5 can constitute a cylinder consisting of at leastsubstantially parallel bristles 4. The tuft 5 of FIG. 13 can haveconcentric annuli of bristles 4 wherein annuli of shorter bristlesalternate with annuli of longer bristles. Alternatively, the tuft 5 ofFIG. 13 can resemble the leftmost or the rightmost tuft 5 in the brush 3of FIG. 10, i.e., the effective length of the centrally located bristles4 exceeds the effective length of outer bristles and the effectivelength of the bristles can decrease from the center toward the peripheryof the tuft 5 so that the tip of the tuft resembles a hemisphere or acone.

FIG. 1b shows a further form 207 wherein the effective depth of thesockets 206 can be varied by a set of discrete pistons 206d connected toa main piston 206e which is reciprocable between the chambers 206f, 206gof a double-acting fluid-operated cylinder 206h. A projection or stop206i in the chamber 206g limits the extent of movability of pistons 206din the respective cylinder chambers or holes 206j of the form 207 in adirection away from the open ends of the corresponding sockets 206. Theform 207 is further provided with channels 223a which perform thefunctions of channels 123a shown in FIG. 1a and are connected to asuction chamber, not shown in FIG. 1b. The pistons 206d define thebottom surfaces 221 in the respective sockets 206. FIG. 1b shows concavebottom surfaces 221; however, it is equally possible to provide some orall of the pistons 206d with flat, convex, undulate and/or otherwiseprofiled bottom surfaces.

The main piston or plunger 206e is moved in synchronism with theoperation of certain other parts of the apparatus which embodies theform 207 of FIG. 1b. Thus, the pistons 206d can be retracted to theirdeepmost or rearmost positions (in which the main piston 206e abuts theprojection or stop 206i) during drawing of bristles into the sockets 206as a result of evacuation of air via channels 223a. The pistons 206d arethereupon caused to move to extended positions (to reduce the effectivelength or depth of the respective sockets 206) preparatory toenlargement of the outer or exposed end portions of the bristles in thethus shortened sockets 206.

The main piston 206e can be omitted if the channels 223a are used tolift the pistons 206d and if such channels can also receive compressedair to push the respective pistons 206e back to their innermost orrearmost positions.

An advantage of the form 207 is that it even more reliably ensures thatthe bristles of each tuft assume predetermined axial positions prior towelding of their exposed ends to each other, to the bristles of theneighboring tufts and/or to the cover of a composite form. This is dueto the fact that, if one or more bristles happen to lag behind theothers (i.e., if all of the bristles do not abut the respective bottomsurfaces 221 when the step of evacuating air from the sockets 206 iscompleted), the pistons 206e compensate for such failure of certainbristles to abut the bottom surfaces 221 by moving toward the open endsof the sockets 206 in order to move the bottom surfaces 221 against ornearer to the lagging bristles. Such lagging of certain bristles duringevacuation of air from the sockets 206 is more likely to occur if themeans for drawing air from the sockets 206 includes channels 223a inlieu of one or more foraminous inserts 22.

As can be seen in FIG. 3, a form 7, 107 or 207 (FIG. 3 shows a form 7)can be provided with a large number (fourteen) of sockets 6, and thecross-sectional areas of all of the sockets need not be the same. Theleftmost socket 6 of FIG. 3 has a polygonal (e.g., square)cross-sectional outline, each of the two rightmost sockets 6 has asubstantially oval cross-sectional outline, and each of the remainingsockets 6 has a substantially circular cross-sectional outline.Furthermore, the additional (circular) sockets 6 include larger-diameterand smaller-diameter sockets. The distribution of sockets in a form candepart considerably from that which is shown in FIG. 3; for example, thesockets can form a substantially rectangular or square or circular array(instead of the substantially oval array which is shown in FIG. 3).

One of the magazines 15 which are shown in FIG. 2 can contain relativelythick bristles 4 and the other magazine 15 can contain thinner bristles.Thus, the array 2 which is to be assembled in the form 7 of FIG. 3 caninclude a certain number of tufts consisting of thicker bristles and acertain number of tufts consisting of thinner bristles. Furthermore,certain sockets 6 of FIG. 3 can receive (relatively thick) discretebristles and certain sockets can receive tufts of (relatively thinand/or relatively thick) bristles. Still further, one of the magazines15 which are shown in FIG. 2 can comprise bristles of a first colorand/or made of a first thermoplastic material, and the other magazine 15can contain bristles of a second color and/or made of a different secondthermoplastic material. For example, the bristles in one of themagazines 15 are readily flexible and the bristles in the other magazineare stiffer. Such selection of bristles in the source of bristlesrenders it possible to mass-produce brushes with bristles and tufts ofbristles and arrays of tufts which exhibit any desired characteristicsas concerns the color, flexibility, quality, diameter and/or otherparameters.

The dimensions of tufts will depend upon the dimensions of correspondingpockets 18 in the transfer member 17. However, the pockets 18 can beformed in such a way that their dimensions merely determine the numbersof bristles which are to be drawn through the respective conduits 10;the cross-sectional outlines of the tufts 5 are then determined by thecross-sectional outlines of sockets in the respective form or forms 7,107 or 207. It normally suffices to properly select the cross-sectionaloutlines of apertures 6a in the covers 14, i.e., and since the endportions 8 of the bristles 4 forming the tuft 5 in the median socket 6of FIG. 1 are not permitted to enter the respective blind hole 6c, theblind hole 6a can be a cylindrical hole even if the tuft 5 is to have anoval or polygonal cross-sectional outline because such cross-sectionaloutline of the tuft is determined by the respective aperture 6a of thecover 14. All that counts is to ensure that each bristle 4 of a tuft 5which is to be assembled in a selected socket 6 can partially penetrateinto the corresponding blind hole 6c so that all bristles contact therespective bottom surface 21.

The distribution of pockets 18 in one or both sides 16 of the transfermember 17 can depart from the distribution which is shown in FIG. 2. Forexample, the sides 16 need not be flat (i.e., the pockets 18 in suchsides need not form straight rows) if the walls 18 (or those portions ofthe walls 18a which are adjacent the respective sides 16 of the transfermember 17) are made of an elastomeric material which can be deformed (bythe cylinder-and-piston units 18b or in any other way) into sealingengagement with concave, convex and/or otherwise configurated sides ofthe member 17.

The maximum number of pockets 18 in each of the sides 16 can also departfrom the numbers which are shown in FIG. 12. Moreover, the number ofpockets 18 in one of the sides 16 can be a small or a large fraction ofthe number of pockets in the other side 16.

By way of example, and if the apparatus is to cyclically produce sets offour brushes 3 at a time, the source of bristles can contain fourmagazines 15 with one transfer member 17 for each pair of magazines, andeach such transfer member is then provided with a number of pocketscorresponding to the combined number of sockets in two forms 7, 107 or207. It is also possible to employ a discrete transfer member for eachmagazine, or to employ a first transfer member in a manner as shown inFIG. 2 (i.e., for withdrawal of bristles from two neighboring magazines)and one or more additional transfer members each of which serves to drawbristles from a single magazine.

As already mentioned above, the inner diameters of the conduits 10 canbe within the range of 0.1 to 20 mm. It is presently preferred to employconduits with inner diameters in the range of 1 to 10 mm, mostpreferably in the range of 2 to 5 mm. The length of the conduits 10 isnormally within the range of 1 to 10 meters, for example, approximately5 meters. Conduits having the aforementioned inner diameters and alength of 1 to 10 meters have been found to permit predictableadvancement of discrete bristles or tufts of bristles from the sourceand all the way into contact with the bottom surfaces 23, 123 or 223 inthe respective sockets 7, 107 or 207. The exact length of the conduits10 will depend upon the dimensions of the space which is available forinstallation of the improved brush making apparatus and/or upon certainother considerations. The conveying means of the improved apparatus caninclude shorter, medium long and longer conduits (this can be seen inFIGS. 1 and 4).

FIG. 4 shows that the number of conduits 10 in an apparatus 1 can exceedthe number of sockets 6 in a form 7. For example, each of the set offorms 7 which are shown in FIG. 4 can have nine suitably distributed orarrayed sockets 6. On the other hand, the number of conduits can equal ntimes m wherein m is the number of sockets 6 in a form 7 and n is awhole number including two or more. Two additional conduits are shown inFIG. 4 at 10A; these conduits form part of at least one set of nineconduits which are provided in addition to the conduits 10 and serve toconvey discrete bristles and/or tufts of bristles from the source (forexample, a source comprising one or more magazines 15 of the type shownin FIG. 2) to a second form 7 behind the form at a bristle- ortuft-admitting station 29a of FIG. 4.

The number of conduits will depend on the desired output of the brushmaking apparatus and on the number of sockets in a discrete form 7, 107or 207.

FIG. 4 further shows that the apparatus 1 can comprise means fortransporting one or more groups of successive forms 7 and main sections7a along a predetermined (preferably endless) path. The illustratedtransporting means comprises an endless belt or chain conveyor 24 whichis trained over pulleys or sprocket wheels 24a to advance the preferablyequidistant forms 7 and main portions 7a of forms 7 in the direction ofarrow Pf2. The forms 7 and main sections 7a are advanced stepwise by asuitable prime mover 24b. The introduction of bristles and/or tufts ofbristles takes place into successive forms 7 which reach the admittingstation 29a adjacent the substantially horizontal upper reach or stretchof the conveyor 24, and the expulsion of bristles and tufts of bristlesof finished brushes 3 from the blind holes 6c of the respective mainsections 7a takes place at a station 28 which is adjacent the lowerreach or stretch of the conveyor 24.

A main section 7a is temporarily (detachably) coupled with a cover 14 ata station 29 which is located upstream of the station 29a. Covers 14 aresupplied by a source 14a, and the means for transferring covers from thesource 14a to successive main sections 7a which reach the station 29 caninclude tongs, a chute for gravity feed of covers or any other suitablecover delivering means.

The station 29a, at which successive fully assembled forms 7 (eachincluding a main section 7a which is overlapped by a cover 14) receivearrays 2 of bristles 4 and/or tufts 5, is followed by a station 29bwherein the exposed ends 8 of the bristles 4 extending into therespective sockets 6 are enlarged by a reciprocable or otherwise movableheating device 25 serving to heat the end portions 8 at least close tothe melting point of the material of the bristles 4 and to force thethus softened end portions 8 into the respective apertures 6a so thatthe softened end portions are bonded to the corresponding cover 14, tothe other bristles 4 of a tuft 5 and/or to the end portions 8 ofbristles 4 in one or more neighboring apertures 6a. All that counts isto ensure that the end portions 8 are properly bonded (e.g., welded) tothe respective cover 14 because the latter constitutes or can constitutea component part of the respective brush 3. It is also possible toreliably secure the end portions 8 to the respective covers 14 by thesimple expedient of mechanically deforming the end portions 8 and/or byspraying an adhesive onto the end portions 8 prior to deformation ofsuch end portions into engagement with neighboring end portions 8 and/orinto engagement with the cover 14.

The station 29b is followed by a station 29c where the covers 14 (eachof which is already connected with the corresponding array 2 of bristles4 and/or tufts 5) are overlapped by brush bodies 26 (actually by mainportions of brush bodies) which are drawn from a suitable source 26a,e.g., in the same way as described for withdrawal of covers 14 from therespective source 14a at the station 29. The brush bodies 26 arepermanently or detachably affixed to the respective covers 14 at atreating station 29d which accommodates a reciprocable affixing ortreating device 27, e.g., an ultrasonic welding device or an adhesiveapplicator coupled with a ram or a like part capable of urging the brushbodies 26 against the respective covers 14. This completes the making ofa brush 3, and such brush is thereupon advanced to the station 28 whereits bristles are expelled from the blind bores 6c of the respective mainsection 7a, e.g., by admitting compressed air into the correspondingsuction chamber 23 and/or by exerting a pull upon the correspondingbrush body 26 in a direction to extract the bristles from their blindholes 6c. The descending brushes 3 can be intercepted by a take-offconveyor (not shown) or gathered in a suitable receptacle, not shown.The main sections 7a advance beyond the station 28 toward the station 29where they are temporarily coupled with freshly supplied covers 14.

The covers 14 can be made of the same material as the brush bodies 26.This simplifies permanent bonding of covers (and arrays 2 of bristlesand/or tufts) to the respective brush bodies. For example, the covers 14and the brush bodies 26 can be made of a suitable syntheticthermoplastic material which is heated at the station 29d to atemperature necessary to ensure predictable and reliable bonding of eachcover to the respective brush body. If the covers 14 are to beadhesively secured to brush bodies 26, the materials of these parts willbe selected with a view to ensure the establishment of a reliable bondbetween each cover and the respective brush body. The exposed ends ortips of bristles 4 forming part of a finished brush 3 are those endswhich were maintained in abutment with the respective bottom surfaces23, 123 or 223 preparatory to and during enlargement of the other endportions 8 and during transport of forms toward the evacuating orexpelling station 28.

FIG. 8 shows a brush body 26 and a slightly modified cover 114immediately or shortly prior to arrival of the corresponding form 7 atthe station 29d of FIG. 4, and FIG. 10 shows a portion of a finishedbrush 3, i.e., the cover 14 is already received in a complementaryrecess or depression 31 of the brush body 26. The enlarged end portions8 of the bristles 4 are fully concealed by the parts 14 and 26.

Referring again to FIG. 8, the modified cover 114 has a flange or collar30 which overlies the adjacent side of the brush body 26 when the majorportion of the cover 114 is received in the recess 31 of the brush body.The flange or collar 30 is or can be a circumferentially complete framewhich surrounds the array 2 of tufts 5 and surrounds the entire recess30 when the assembly of the cover 114 with the brush body 26 iscompleted. An advantage of the flange or collar 30 is that it canprolong the useful life of a brush (such as the toothbrush 3 of FIG. 8)because it greatly reduces the likelihood of penetration of water and/ortoothpaste and/or fragments of food into the recess 31.

FIG. 4 further shows that it is not necessary to transport complete mainsections 7a toward and beyond the bristle- or tuft-admitting station29a. Thus, it suffices to connect the conveyor 24 with the components7a' (FIG. 1) of the main sections 7a and to employ a single component7a" which is movable up and down (arrow 24c in FIG. 4) into and fromsealing engagement with the component 7a' which has arrived at thestation 29a. This simplifies the apparatus because it is only necessaryto provide a single conduit C and a single valve V. The means for movingthe component 7a" at the station 29a comprises a fluid-operated cylinderand piston assembly 24d or any other suitable reciprocating means. Atleast a portion of the conduit C can constitute a flexible hose topermit movements of the single component 7a" into and from sealingengagement with the component 7a' at the station 29a.

FIG. 5 shows that the adapter or cover 14 need not always be providedwith apertures 6a having diverging portions (shown at 6b in FIG. 1)which are remote from the main section 7a of the form 7. FIG. 5 furthershows that the end portions 8 of the bristles 4 can remain outside ofthe respective apertures 6a when the heating step is completed. On theother hand, the end portions 8 of bristles 4 which are shown in FIG. 6are confined in the enlarged (diverging) portions 6b of the respectiveapertures 6a, and the end portions 8 of bristles in neighboringapertures 6a actually contact and are bonded to (melted into) each otherto further enhance the stability of connection between the tufts 5 andthe cover 14. The enlarged portions 6b of neighboring apertures 6a inthe cover 14 of FIG. 6 communicate with each other at that side of thecover which faces away from the main section 7a. This is even moreclearly shown in FIG. 7 wherein the end portion 6a of each aperture 6acommunicates with at least two neighboring end portions 6a. This rendersit possible to bond several bristles of each tuft to several bristles ofthe tufts in neighboring sockets 6 of the form utilizing the cover 14 ofFIG. 7. The heating device 25 can readily deform the softened endportions 8 of the bristles 4 so that the deformed end portions 8 impartto the respective ends of the tufts a shape corresponding to that whichis shown in FIG. 6, i.e., the deformed and enlarged end portions 8 atleast partially fill the respective apertures 6a and several bristles ofeach tuft are bonded to the bristles of two or more neighboring tufts.In addition, the bristles of each tuft are bonded to each other and tothe cover 14.

The arrangement may be such that the deforming action upon the softenedend portions 8 of the bristles 4 is completed exclusively by the heatingdevice 25 of FIG. 4 (FIG. 6), exclusively by the affixing device 27(FIG. 10), or in part by the device 25 and in part by the device 27.Alternatively, and if the apparatus of FIG. 4 further comprises acomponent 7a" at the station 29b, the softened end portions 8 of thebristles 4 (such softened end portions can have a doughy consistency)can be drawn into the respective enlarged portions 6b by suction to setduring advancement of the respective components 7a' toward and past thestation 29c. This ensures reliable bonding of the enlarged and deformedend portions 8a of bristles in each tuft to each other as well as (ifdesired) to the end portions 8 of bristles in neighboring tufts (FIGS. 6and 7) and to the respective covers 14 or 114. Such drawing of thematerial of softened end portions 8 deeper into the respective apertures6a enlarges the bonds between neighboring bristles of each tuft andthereby further ensures the establishment of a large-area bond betweenthe end portion of each tuft and the surface bounding the respectiveaperture 6a of the cover 14 or 114.

FIGS. 14 and 15 show that the covers 14 can be provided with projectionsor protuberances 33 at those sides which face away from the respectivemain sections 7a. These covers (or at least their projections 33) aremade of a thermoplastic material so that the protuberances are softenedand deformed as a result of heating at the station 29b of FIG. 4. Thisensures that the softened projections 33 are reliably bonded to theadjacent softened end portions 8 of the bristles 4, i.e., the areas ofbonds between the bristles 4 and the cover 14 are enlarged to furtherreduce the likelihood of accidental extraction of bristles from the bodyof a finished brush. The projections 33 can have a circular, oval orpolygonal outline and each aperture 6a of the cover 14 can be surroundedby an annulus of discrete projections or by a circumferentially completeprojection. The material of the covers 14 which are shown in FIGS. 14and 15 can be the same as the material of the bristles 4; this rendersit even more likely that the softened projections 33 will be reliablybonded to the end portions 8 of the adjacent bristles 4. However, it isequally within the purview of the invention to make the covers 14 ofFIGS. 14 and 15 of a material other than the material of the bristles 4,as long as the softened end portions 8 of the bristles can be reliablybonded to the softened projections 33.

Referring to FIG. 7, the projections 33 can be distributed on the cover14 in such a way that they fill the spaces 6b' between the communicatingenlarged portions 6b of the apertures 6a so that the deformed endportions 8 of bristles in such apertures and the deformed projections ofthe cover 14 form a practically uninterrupted layer of hardenedthermoplastic material to even further reduce the likelihood ofextraction of bristles from the body of the finished brush. Portions ofsoftened projections 33 can be caused to flow into the adjacentapertures 6a to even further reduce the likelihood of accidentalextraction of bristles 4 and/or the likelihood of penetration of germs,toothpaste, fragments of food and/or water between a cover 14 and thecorresponding brush body 26 if the ultimate product is a toothbrush.

FIG. 9 shows that the body 26 of a brush 3 can include an integralportion which forms a cover 214. This renders it possible to replace thesource 14a of FIG. 4 with the source 26a. Moreover, it is then possibleto dispense with the affixing device 27 of FIG. 4 because the making ofbrushes 3 is completed at the station 29b. FIG. 9 further shows aplate-like lid 32 which can be inserted into a recess 26b of the brushbody 26 to conceal the enlarged (deformed) end portions 8 of bristles inthe tufts forming the array 2. The lid 32 can be a press fit in therecess 26b or such lid can be bonded (e.g., adhesively or by welding) tothe brush body 26. The provision of a lid 32 is particularly desirableif the bristles of each tuft are connected only to each other and/or tothe cover 214 but not to the end portions 8 of bristles in the adjacenttufts (see FIG. 5).

The operation of the improved apparatus can be automated to any desiredextent. Furthermore, the output of the apparatus can be increases stillfurther if the conveyor 24 is driven continuously rather thanintermittently; it is then necessary to provide means for moving theheating device 25 and the affixing device 27 through a certain distancein and counter to the direction of arrow Pf2 so that the device 25shares the movement of the adjacent form 7 during heating of endportions 8 of the bristles 4 and that the affixing device 27 shares themovements of a component 7a', a cover 14 and a brush body 26 in thedirection of arrow Pf2 while the body 26 is being secured to theadjacent cover 14. Irrespective of the nature of drive means for theconveyor 24 (i.e., regardless of whether the conveyor 24 is drivencontinuously or stepwise), the end portions 8 of bristles 4 which wereinserted at the station 29a are being heated at the station 29b whilethe sockets 6 at the station 29a are in the process of receivingdiscrete bristles or tufts of bristles via conduits 10.

The output of the improved brush making apparatus considerably exceedsthe output of a conventional apparatus wherein tufts of bristles areindividually inserted into the sockets of a brush body. Moreover,anchoring of tufts 5 in the brush bodies is more uniform than inaccordance with heretofore known procedures because the operation of theimproved conveying means (including means for drawing bristles into thesockets 6 by suction P) is much more predictable and more uniform thanconventional mechanical insertion of discrete tufts. Insertion of alarge number of tufts into the sockets of a form by suction takes upless time than the insertion of a single tuft in accordance withheretofore known proposals. In addition, the improved apparatus rendersit possible to rapidly shift from operation with identical bristles tooperation with differently dimensioned and/or colored bristles as wellas to impart to the exposed tips of tufts 5 any desired shape which isbest suited for a particular purpose, e.g., for a toothbrush, for apaintbrush, for a clothes brush or for any other type of brush. It isequally possible to select, practically at will, the cross-sectionaloutlines of the tufts 5 as well as the distribution of tufts in an array2. All that is necessary is to rearrange the discharge ends 12a of theconduits 10, 10A and to employ a different set of forms having socketsin a desired distribution.

If the improved apparatus is used for the making of paintbrushes of thetype used by artists (with a single tuft of bristles), a form 7, 107 or207 can be used for simultaneous making of a number of discretepaintbrushes. The end portions 8 of bristles 4 in each tuft 5 are thenconnected to one end of a discrete brush body in the form of anelongated handle. Such brushes can be made without resorting to covers14, 114 or any other covers because the softened end portions 8 ofbristles 4 in each of two or more tufts 5 in a main section 7a can bebonded directly to one end of an elongated handle-like brush body.

The apparatus of FIG. 14 differs from the apparatus of FIG. 1 (a) inthat it employs covers 14 with the aforediscussed projections orprotuberances 33 and (b) in that it employs a modified support 120 forthe discharge ends 12a of the conduits 10. The passages 111 of thesupport 120 contain flow restrictors 34 in the form of venturis whichcause desirable acceleration of bristles 4 on their way from theconduits 10 into the sockets 6 of the form 7 at the station 29a. Eachpassage 111 narrows in a direction from the discharge end 12a of therespective conduit 10 toward the cover 14, and its width thereuponincreases gradually (at 35) to form a throat approximately midwaybetween the upper side and the underside of the support 120.

The support 120 of FIG. 14 will be put to use when certain bristles 4 oftufts 5 in the conduits 10 exhibit a tendency to lag behind the otherbristles. For example, the outer bristles of a tuft (namely those whichcontact the internal surface of the respective conduit 10) tend to lagbehind the bristles at the center of the respective tuft. The flowrestrictors 34 effect an acceleration of all bristles in the tufts 5 tothus further increase the likelihood that the leading end of each andevery bristle will reach the bottom surface 21 in the respective socket6 of the form 7. In other words, the flow restrictors 34 ensure that thekinetic energy of each bristle in a tuft suffices to guaranteepredictable introduction into the corresponding socket 6. Theutilization of flow restrictors upstream of the sockets 6 is possiblebecause the bristles 4 are drawn into the sockets 6 by suction ratherthan being propelled into the sockets by compressed air or anothercompressed gaseous fluid. The bristles of tufts which are propelled by acompressed gaseous fluid will tend to pile up ahead of a flowrestrictor; therefore, apparatus wherein tufts of bristles aretransported by compressed air are provided with means for securing thebristles of each tuft to each other prior to pneumatic transport of thetufts to the brush forming station.

If a bristle 4 of a tuft 5 which contains several bristles or a verylarge number of bristles fails to fully enter the corresponding socketor does not enter the socket at all, it is simply converted into a massof softened plastic material under the action of the heating device 25and such mass is bonded to the end portions 8 of neighboring (properlyinserted) bristles 4 to even further enhance the stability andreliability of the bond between the end portions 8 of bristles in a tuftwhich is anchored in the cover or directly in the body of a brush.

The apparatus of FIG. 14 can be used with particular advantage for themaking of brushes wherein some or all of the sockets in a form are toreceive very small numbers of bristles or individual bristles. It hasbeen found that the flow restrictors 34 invariably ensure predictablepenetration of discrete bristles all the way into abutment with thebottom surfaces 21 in the respective sockets 6. Moreover, the flowrestrictors 34 can center the leading ends of the bristles 4 which areabout to enter the respective sockets 6 to thus ensure that each suchbristle invariably enters the respective aperture 6a and is not likelyto jam prior to entering the blind hole 6c in the main section 7a of theform 7 at the station 29a.

The sockets of a form will receive discrete bristles if the bristles arevery stiff (e.g., for the purpose of heavy-duty scrubbing) and/or whenthe leading ends of the bristles (i.e., those ends which are exposedwhen the brush is finished) are provided with enlargements in the formof spheres or the like. Such brushes are often used for massaging. Theend portions 8 of individual bristles are deformed (enlarged) in theaforedescribed manner (preferably by softening as a result of heating)and are bonded to the cover and, if necessary, to the end portions 8 ofadjacent discrete bristles or tufts of bristles. The provision ofprojections or protuberances 33 of thermoplastic material alsocontributes to reliable anchoring of end portions 8 of discretebristles.

FIG. 15 shows a portion of an apparatus wherein the conduits 10, 10A areomitted and the transfer member 17 forms part of a means 37 formechanically conveying tufts 5 of bristles 4 (and/or discrete bristles)from one or more magazines 15 to positions of register with theapertures 6a of the cover 14 at the station 29a. The apparatus 1 of FIG.15 preferably further comprises a plate-like guide 38 with openings 39in the form of cylindrical or otherwise configurated holes or bores eachof which registers with the enlarged portion 6b of a discrete aperture6a in the cover 14 at the station 29a. The motor 17a is designed to movethe transfer member 17 between at least one first position in which thepockets 18 (not shown in FIG. 15) of the transfer member receivebristles 4 from the adjacent magazine or magazines 15, and at least onesecond position in which the tufts 5 in the recesses of the transfermember register with the openings 39 of the guide 38 and hence with thesockets 6 of the form 7 at the station 29a.

The lower end portions of the bristles 4 can slide along the upper sideof the guide 38 during transport from the magazine or magazines 15 tothe station 29a. The directions (arrow 17A) of reciprocatory movement ofthe transfer member 17 are substantially at right angles to thelongitudinal directions of bristles in the pockets of the member 17. Theguide 38 can be fixedly mounted in the frame of the brush makingapparatus 1 or is reciprocable or otherwise movable to and from theoperative position of FIG. 15 in which its openings 39 register with theapertures 6a of the cover 14 at the station 29a.

The apparatus 1 of FIG. 15 will be used when it is desirable andpossible to place the source of bristles 4 into close or immediateproximity of the form 7 which is to receive an array of tufts and/ordiscrete bristles. This apparatus is more compact and less expensivethan the apparatus of FIG. 1 or 14 because it need not employ anyconduits and the suction generating device (not shown in FIG. 15) merelyserves to draw bristles 4 and/or tufts 5 of bristles from the pockets ofthe transfer member 17 into the registering sockets 6 of the form 7 atthe station 29a. The transfer or introduction of bristles 4 into thesockets 6 is assisted by gravity if the apparatus is designed in such away that the bristles and/or tufts 5 which are about to be drawn intothe respective sockets 6 are located at a level above the cover 14.

FIG. 16 shows a modified source of bristles which can be utilized inlieu of the source of FIG. 2 in apparatus of the type shown in FIGS. 1and 14 (i.e., in apparatus with conduits for the transport of bristlesand/or tufts of bristles from the transfer member to the form or formsat the station 29a) as well as in apparatus of the type shown in FIG. 15(wherein the transfer member serves to advance bristles and/or tufts ofbristles from one or more magazines directly to positions of registerwith sockets in one or more forms at the station 29a). The source ofbristles which is shown in FIG. 16 comprises a rotary (e.g.,disc-shaped) transfer member 317 with four sets of pockets 318 in itsperipheral surface 316. The peripheral surface 316 seals the open sidesof two magazines 15 which are disposed diametrically opposite each otherwith respect to the axis of rotation of the transfer member 317. Thelatter is indexible in the direction of arrow Pf4, always through anglesof approximately or exactly 90°, and a substantial portion of itsperipheral surface 316 abuts two arcuate walls 318a which prevent escapeof bristles 4 from filled pockets 318 while such pockets advance fromthe open sides of the magazines 15 to locations (at the six and twelveo'clock positions of the transfer member 317, as viewed in FIG. 16)where the bristles and/or tufts of bristles are transferred from thepockets 318 into conduits (not shown in FIG. 16) or directly into thesockets of forms (not shown in FIG. 16). The transfer member 317 candeliver bristles 4 to two discrete sets of conduits or directly to twodiscrete forms. The means for indexing the transfer member 317 in thedirection of arrow Pf4 comprises a shaft 317B and a motor (not shown)which drives the shaft 317B.

An advantage of the structure which is shown in FIG. 16 is that thetransfer member 317 can furnish sets of bristles at frequent intervalsbecause this transfer member need not be moved back and forth, i.e.,each of its stepwise angular movements results in the delivery of twosets of bristles 4 to two sets of conduits or to the sockets of twoforms.

The walls 318a are at least slightly retracted whenever that part of theconveying means which operates by suction is ready to draw bristles fromthe pockets 318 into the adjacent conduits or directly into theregistering sockets of forms at the twelve and six o'clock positions ofthe indexible transfer member 317. This ensures that the bristles 4 canbe withdrawn from the pockets 318 by suction. The same holds true forthe walls 18a which are shown in FIG. 2.

The number of magazines 15 can be increased to three or more, dependingupon the desired output of the brush making apparatus which embodies thestructure of FIG. 16 and upon the diameter of the transfer member 317.The number of sets of pockets 318 in the peripheral surface 316 of thetransfer member 317 is twice the number of magazines to thus ensure thatone-half of the sets of pockets 318 receive bristles while the pocketsof the other half of sets of pockets are in the process of maintainingthe bristles in alignment with the bristle-receiving ends of conduits orwith the openings of the corresponding guides 38 (not shown in FIG. 16).The number of magazines 15 can greatly exceed two; all that counts is toprovide sufficient room between neighboring magazines for transfer ofbristles from sets of filled pockets 318 into the registering conduitsor into the sockets of forms. As shown in FIG. 16, the pockets 318 inthe peripheral surface 316 of the indexible transfer member 317 need notbe identical, i.e., each set of pockets can include one or more largerand one or more smaller pockets as well as pockets having a partlycircular, a partly oval or a polygonal cross-sectional outline.

An important advantage of the improved method and apparatus is that itis not necessary to bond the bristles 4 of tufts 5 to each other priorto anchoring of tufts in the body of a brush. This is due to the factthat loose bristles 4 can be readily drawn into the sockets of a form toassume predetermined positions relative to each other and relative tothe form. Conveying of loose bristles is not possible if the bristlesare to be pneumatically advanced in one or more streams of compressedair or another gaseous fluid. All this contributes to a higher output ofthe apparatus and to higher quality of the brushes. The conveying ofloose bristles by suction is predictable over short as well as overlonger distances; as mentioned above, the conduits 10, 10A can have alength well in excess of five meters, e.g., in the range of ten meters.It has been found that misorientation of bristles is highly unlikely ifthe bristles are conveyed by suction rather than in one or more streamsof compressed air Absence of misorientation practically eliminates thelikelihood of clogging of conduits with misaligned bristles. Suction isor can be assisted by gravity during the last stage of conveying ofbristles into the respective sockets if the sockets are substantiallyvertical with their open ends above and with the bottom surfaces below.All that is necessary is to ensure that the pockets 18 or 318 of thetransfer member 17 or 317 are substantially vertical and that (ifconduits 10 and/or 10A are used) the discharge ends 12a of the conduitsare vertical to direct bristles 4 vertically downwardly into theregistering sockets.

The utilization of one or more forms with adapters or covers also bringsabout a number of important advantages. For example, if the apertures(such as 6a) of a cover (6) have upwardly diverging portions (6b), thesurfaces bounding the upwardly diverging portions steer the leading endsof bristles 4 into the smaller-diameter portions of the respectiveapertures and thence into the blind bores or holes of the main sectionof the respective form. This further reduces the likelihood of jammingat the open ends of the sockets and ensures that the leading ends of thebristles can advance all the way into abutment with the bottom surfacesin the registering sockets. The provision of conical or similar surfacesaround the upper portions of apertures in the cover is particularlydesirable if the apertures are to permit the passage of tufts (i.e.,batches) of bristles.

The cover further serves to maintain the end portions 8 of tufts 5 ofbristles in the respective sockets close to each other in order toensure predictable enlargement (softening and deformation) of such endportions at the station 29b or at any other station where the endportions 8 are heated and thereupon bonded to each other, to the endportions of bristles in neighboring sockets and/or to the cover (e.g.,to the projections 33 of a cover). Still further, the cover acts, or canact, as a heat barrier to prevent softening of those portions ofbristles 4 which have entered the blind holes or bores of the mainsection of a form, namely to prevent softening of those portions of thebristles which are exposed in a finished brush and the appearance and/orany other desirable characteristics of which should not be affected byheat which is applied to soften the end portions 8 at the apertures ofthe cover. A further advantage of the cover is that it can be morereadily secured to a brush body than discrete tufts of bristles orindividual bristles. In addition, and as already described withreference to FIG. 9, each cover (214) can constitute or can form anintegral part of a brush body, i.e., the making of a brush is completedas soon as the bristles and/or tufts or bristles are properly anchoredin the cover. If the cover is a separate part which is thereupon welded,adhesively secured or mechanically affixed to a separately producedbrush body, the cover can shield the major portions of bristles 4 fromheat and/or adhesive during attachment of the cover (with the bristlesanchored therein) to the brush body. This reduces the likelihood ofspraying an adhesive substance and/or molten thermoplastic material ontothe major portions of bristles, i.e., onto those portions of bristles ina toothbrush which come in contact with the teeth and gums of the user.Thus, in addition to performing the function of a thermal barrier, thecover can also serve as a means for shielding the major portions ofbristles from contamination during those stages of brush making whichfollow the anchoring of end portions 8 of bristles 4 in the cover.Moreover, the cover ensures that those portions of bristles which extendbeyond its underside (as seen in FIG. 1) are free to move relative toeach other This guarantees that each bristle of a finished brush 3exhibits a desired elasticity because it is free to move relative to theadjacent bristle or bristles all the way between its exposed end and therespective side of the cover. All this is possible in spite of the factthat the bristles are preferably anchored in the cover as a result ofheating at least close to melting point of their material and subsequentwelding to each other and/or to the cover.

If the cover are separately produced parts, they can be welded,adhesively bonded and/or mechanically secured (e.g., by screws, nails orbolts) to the bodies of the respective brushes. The exact nature ofconnection between a cover and the respective brush body will dependupon the size and desired appearance as well as upon the intended use ofthe brush.

The component 7a" at the station 29b of FIG. 4 renders it possible todraw molten material of the bristles 4 into the respective apertures bysuction. Since the suction can be regulated with a high degree ofaccuracy, the apparatus employing a component 7a" at the station 29bensures predictable filling of apertures 6a with thermoplastic materialof end portions 8 of the bristles to thus ensure the establishment ofreliable bonds between the end portions 8 themselves as well as betweensuch end portions and the respective cover. However, it is equallywithin the purview of the invention to force molten material of endportions 8 into the respective apertures 6a by mechanical means and/orby a pressurized fluid. Thermoplastic material which sets in theapertures 6a of a cover at the station 29b maintains the bristles of therespective tufts in a desired orientation, and such thermoplasticmaterial also serves as a seal which prevents penetration of germs,moisture, toothpaste, food particles, saliva and/or other foreign matterbetween a cover and the respective brush body.

Once a cover is properly secured to the respective brush body, thebristles which extend into the apertures of such cover are reliably heldin optimum positions even if the end portions 8 of the bristles are notbonded to the cover (see FIG. 5). Thus, the connection between a coverand the respective brush body suffices to hold the bristles of thefinished brush in proper positions relative to each other and relativeto the brush body even if the bristles are not positively secured to thecover. It often suffices to install a cover in the respective brush bodyby friction; however, it is normally desirable to establish a morereliable and preferably permanent connection between a cover and a brushbody. A more or less permanent connection is established by welding(e.g., high frequency welding), by the utilization of a suitableadhesive or by screws, nails or other fasteners. The establishment of areliable connection between a cover and a brush body can or will resultin at least some deformation of substantially spherical heads which areshown in FIG. 5 and are obtained as a result of melting of end portions8 of bristles 4 which extend through the cover and into the blind boresor holes 6c of the main section 7a of the form 7. Such deformation ofspherical formations consisting of molten end portions 8 of bristles 4ensures reliable anchoring of tufts 5 in the body of the finished brush.

The covers can be used for the making of brushes which containrelatively soft (readily flexible) bristles, relatively stiff bristlesor arrays of bristles having different characteristics including color,diameters, composition and/or others. All that is necessary is toproperly distribute different types of bristles in two or more discretemagazines 15. Differently colored bristles will be used to enhance theappearance of the brushes and/or to form a symbol, e.g., the trademarkof the maker, the initials of the maker and/or other information.

The utilization of two or more different types of bristles does notaffect the output of the improved brush making apparatus. Thus, thesource of FIG. 2 or the source of FIG. 16 can supply discrete bristlesor batches of bristles at a high frequency irrespective of whether theplural magazines 15 contain identical or different bristles.Furthermore, and since the bristles which are conveyed to positions ofalignment with the sockets of one or more forms are drawn into therespective sockets by suction, the means for drawing the bristles intothe aligned sockets can effectively perform its function irrespective ofwhether the bristles which are about to be drawn by suction are black,white, transparent, opaque, short, long, thick or thin. If the means fordrawing bristles into registering sockets also serves to draw bristlesthrough conduits 10 and/or 10A, the likelihood of clogging of theconduits with bristles is practically nil, as long as the bristles aresufficiently flexible to undergo requisite deformation (flexing) duringadvancement through arcuate portions of the respective conduits. Thepassages 19 in the carrier 13 for the bristle-receiving ends 12 of theconduits 10 and/or 10A also contribute to a reduction of likelihood, orelimination, of clogging of receiving ends 12 with bristles, especiallyif the surfaces bounding the passages 19 are configurated in a manner asshown in FIG. 1. It has been found that the conveying of discretebristles and/or batches of loose bristles from the source of bristles tothe sockets of a form takes up surprisingly short intervals of time,even if the conduits are several meters long.

The flow restrictors 34 of FIG. 14 constitute an advantageous anddesirable but optional feature of the improved brush making apparatus.It has been found that suction in the sockets of a form can cause allbristles of a tuft to enter the respective socket and to come intoabutment with the respective bottom surface even if the speed of allbristles forming the tuft is not the same during advancement through aconduit 10 or 10A. In most instances, all bristles of a tuft willadvance at the same speed; however, any stragglers will simply travel alittle longer prior to coming into abutment with the bottom surface atthe lower end of the respective socket. This also holds true if theapparatus does not employ any conduits between the source of bristlesand the station 29a or an analogous station, e.g., if the bristles andtufts of bristles are transferred by mechanical means in a manner asdescribed with reference to FIG. 15. Moreover, and as already describedabove, the exposed ends of tufts in a finished brush can assume adesired shape by the simple expedient of properly profiling the bottomsurfaces which intercept the bristles and arrest the bristles inpredetermined axial positions with reference to the corresponding form.

The support 20 or 120 can be moved relative to one or more forms at thestation 29a by a fluid-operated motor or in any other suitable way.Similar motor or motors can be used to move the component 7a" at thestation 29a relative to the conveyor 24, to move the component 7a" atthe station 29b relative to the conveyor 24, to move the heating device25 relative to the adjacent component 7a' and cover 14 at the station29b, to move the device 27 at the station 29d and/or to move the ejectoror ejectors for brushes 3 at the station 28 (provided that the apparatusdoes not employ only a pressurized fluid as a means for expelling thebristles of finished brushes 3 from successive components 7a' at thestation 28).

The flow restrictors 34 of FIG. 14 can be used with advantage inapparatus wherein each socket 6 or certain sockets of the form 7 are toreceive large numbers of bristles 4. The accelerating action upon thebristles 4 can be varied by replacing the illustrated support 120 with asupport having a set of different flow restrictors which can effect amore pronounced or less pronounced acceleration of bristles on their wayin the conduits 10 as well as on their way from the discharge ends 12aof the conduits 10 into the registering sockets 6. FIG. 14 further showsthat the inner diameters of the conduits can match the diameters ofupper portions of passages 19 in the carrier 13 for thebristle-receiving ends of the conduits.

The leading ends of the bristles 4 can be rounded to further reduce thelikelihood of jamming in the passages 19 of the carrier 13 and/or in theapertures of a cover at the station 29a. Rounded leading ends ofbristles are more likely to penetrate into narrow spaces between otherbristles of a tuft 5 if one or more bristles lag behind the otherbristles of a tuft during advancement along the path which is defined bythe respective conduit 10 or 10A, i.e., even a slower bristle having arounded leading end will be capable of reaching the respective bottomsurface 21 because such rounded leading end will find its way betweenthe bristles which already abut the bottom surface. Furthermore, if abristle happens to project well beyond the end portions 8 of bristleswhich already abut a bottom surface 21, such projecting bristle issimply melted by the heating device 25 and ensures the establishment ofa more reliable bond between the end portions 8 of other bristles orbetween such end portions and the cover 14.

The profiled bottom surfaces 21, 121 and 221 render it possible todispense with the step of trimming the exposed ends of tufts 5 in afinished brush 3. This brings about substantially savings in time andequipment. Moreover, the profiled bottom surfaces ensure that the tipsof tufts in each of a short or long series of successively and/orsimultaneously produced bristles will have an optimum configurationwhich is complementary to the profiles of the respective bottomsurfaces.

It has been found that the channels 123a and 223a which are shown inFIGS. 1a and 1b ensure predictable penetration of bristles 4 all the wayinto abutment with the respective bottom surfaces 121 and 221 eventhough the intake ends of these channels are not provided in the bottomsurfaces. The reason is that the inertia of bristles which are in theprocess of entering the sockets 106 or 206 suffices to ensure that theleading ends of the bristles advance beyond the intake ends of thechannels 123a or 223a and actually abut the bottom surfaces 121 or 221.On the other hand, the provision of channels with intake ends which areremote from the bottom surfaces 121 and 221 is desirable andadvantageous because such channels are not likely to be clogged by theleading ends of bristles 4 even if the diameters of leading ends exceedthe average diameters of the bristles. The pores of a foraminous insertwhich is made of sintered metallic or ceramic material, felt or the likeare too small to permit penetration of leading ends of bristles;therefore, the bottom surfaces 21 can be provided on or in such insertsto thus ensure that the leading ends of the bristles can be drawn bysuction all the way to the bottom surfaces.

The bottom surfaces can be profiled in such a way that they maintain thebristles in the respective sockets in any desired axial positions. Forexample, the depth of the valleys in the bottom surface 21 which isshown in FIG. 11a can be very small so that the differences between theeffective lengths of bristles in the tufts of FIG. 11 are equally small.On the other hand, even such small differences can contribute to theappearance and/or utility of the finished brushes. For example, thecleaning action of a toothbrush having tufts 5 with shorter and longerbristles 4 in a distribution as shown in FIG. 11 is much moresatisfactory than that of a toothbrush wherein all bristles of a tufthave identical lengths. Of course, the bottom surface 21 of FIG. 11a canhave a concave, convex, sloping and/or other profile in addition toexhibiting the illustrated hills and valleys. This can even furtherenhance the utility of the finished product. For example, thedistribution of bristles 4 in the longer tufts 5 of FIG. 10 can besimilar to that of bristles in the tufts of FIG. 11, i.e., the free endor tip of a tuft 5 can have a rounded shape and, in addition, the freeends of bristles in the tuft need not form an ideal hemisphere butrather a hemisphere wherein some free ends project beyond the others tothus further enhance the cleaning effect and/or the appearance of thebrush. Such profiling of the tips of tufts is much more complex andexpensive if it is achieved as a result of trimming of tufts in afinished brush; on the other hand, mere profiling of bottom surfaces 21suffices to ensure the formation of tufts with simple, more complex orvery complex configuration of their tips. Forms (207) of the type shownin FIG. 1b can be used with particular advantage if the tips of tufts 5are to be configurated in a rather specific way because a shifting ofpistons 206d toward the open ends of the respective sockets 206 greatlyreduces the likelihood that one or more bristles would be out of contactwith the respective bottom surfaces 221 prior to bonding of end portions8 of bristles to each other and/or to the cover.

The improved apparatus can employ a single magazine 15 or two or moremagazines. Furthermore, each magazine 15 can cooperate with a discretetransfer member (such as 17), or a single transfer member (17 or 317)can draw bristles 4 from two, three or more magazines.

The appearance of the finished brushes can be enhanced by employingbristles 4 of different colors and/or by assembling covers having one ormore first colors with brush bodies having one or more second colors.The surfaces bounding the apertures in the covers can be configurated insuch a way that the bristles of a finished brush are substantially orexactly parallel to each other. Alternatively, these surfaces can beconfigurated to facilitate or cause at least some spreading of bristles(e.g., bristles of a tuft) in a direction from the cover toward the freeends of the bristles This might be desirable in certain brushes toenhance their cleaning, massaging and/or other effect. For example,so-called open tufts can be obtained in the lower portions of apertures6a in the cover 14 of FIG. 1 are bounded by conical surfaces whichdiverge toward the main section 7a of the form 7. Such configurationscan be achieved without resorting to so-called anchors which exertpressure upon individual bristles.

A further important advantage of the means for drawing bristles 4 bysuction is that particles of dust which develop during grinding ofbristles to impart to their leading ends a spherical shape is much lesslikely to continue to adhere to the bristles when the introduction ofbristles into their sockets is completed. When a brush (e.g., atoothbrush) is produced in accordance with heretofore known methods, thebristles of the finished article often carry a rather large number ofdust particles.

The introduction of bristles into sockets by suction and subsequentfixing of end portions 8 of introduced bristles to each other and/or tothe cover renders it possible to dispense with the conventionalanchoring of bristles and the resulting development of notches which canlead to cracks. Moreover, and since it is not necessary to developnotches, individual bristles are less likely to penetrate into notchesand to project from other bristles in an orientation which isundesirable because it detracts from the appearance of the finishedbrush and also because the thus misoriented bristle does not contributeto the cleaning or other desirable action of the brush.

Each tuft of FIG. 5 can be used as part of a paintbrush, particularly anartists' brush. All that is necessary is to attach the spheres which areformed by the molten-together end portions 8 of bristles to the ends ofsuitable handles or to break up the cover 14 of FIG. 5 into sections andto use each section for attachment to a suitable handle.

The projections 33 which are shown in FIGS. 14 and 15 constituteoptional features of the covers 14. If such projections are used, thedevice 25 of FIG. 4 must generate sufficient heat to soften or melt theprojections and to thereupon deform the softened projections intoengagement with softened end portions 8 of adjacent bristles 4. Asalready described with reference to FIG. 7, the deformed projections 33can fill the spaces 6b' between the enlarged portions 6b of apertures 6ain a cover 14 to thus ensure that the end portions 8 of all bristles andthe deformed projections 33 together form a film or layer of hardenedthermoplastic material which ensures a highly reliable anchoring ofbristles in the cover 14 and hence in the body of the finished brush.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic and specific aspects of my contributionto the art and, therefore, such adaptations should and are intended tobe comprehended within the meaning and range of equivalence of theappended claims.

I claim:
 1. A method of making brushes from bristles in at least one form which is permeable to gaseous fluids and has bristle-receiving open-ended sockets, comprising the steps of establishing and maintaining at least one supply of bristles; conveying predetermined numbers of bristles from the at least one supply to the sockets of the at least one form, including drawing air from the sockets through the at least one permeable form so that the bristles are introduced into the sockets by suction and portions of the thus introduced bristles are located at the open ends of the respective sockets; and enlarging said portions of the bristles at the open ends of the respective sockets.
 2. The method of claim 1, said bristles being made of thermoplastic material, wherein said enlarging step includes heating said portions of the bristles at least close to the melting point of the thermoplastic material of the bristles
 3. The method of claim 1, wherein each of said predetermined numbers of bristles constitutes a tuft of at least substantially parallel bristles and said conveying step further comprises establishing for said tufts, discrete at least substantially sealed paths from the at least one supply to the respective sockets so that drawing of air from the sockets entails the advancement of tufts along the respective paths and into the respective sockets.
 4. The method of claim 1, wherein said conveying step includes introducing the bristles into the respective sockets by moving the bristles substantially vertically downwardly so that said portions constitute the trailing upper ends of the introduced bristles.
 5. The method of claim 1, wherein said at least one form has a main section with major parts of the sockets and a cover which overlaps the main section and has neighboring apertures constituting the open ends of the sockets, said portions of introduced bristles extending at least into the respective apertures of the cover.
 6. The method of claim 5, wherein said enlarging step includes bonding said portions of the bristles to the cover.
 7. The method of claim 5, wherein said enlarging step includes bonding said portions of bristles in neighboring apertures of the cover to each other.
 8. The method of claim 5, wherein each of said predetermined numbers constitutes a tuft of at least substantially parallel bristles and said enlarging step includes bonding said portions of at least two bristles in each of said tufts to each other.
 9. The method of claim 5, wherein said at least one form with a cover has at least one projection adjacent each of the apertures therein, said enlarging step includes bonding said portions of at least some introduced bristles to the adjacent projections of the cover.
 10. The method of claim 5 wherein each aperture has a portion remote from and diverging in a direction away from the main section, said enlarging step including heating said portions of the bristles in the enlarged portions of the respective apertures.
 11. The method of claim 5, said bristles being made of thermoplastic material, wherein said enlarging step includes heating said portions of inserted bristles at least close to the melting point of the thermoplastic material of the bristles so as to soften said portions of introduced bristles, and further comprising the step of at least partially forcing the softened portions of bristles into the respective apertures of the cover.
 12. The method of claim 11, wherein said forcing step includes drawing the softened portions of introduced bristles into the respective apertures by suction.
 13. The method of claim 11, wherein each of said predetermined numbers constitutes a tuft of substantially parallel bristles and said forcing step includes bonding the softened portions of bristles in each tuft to each other and/or to the cover.
 14. The method of claim 5, further comprising the step of separating the cover and the bristles from the main section of the form.
 15. The method of claim 14, further comprising the step of securing the separated cover and the bristles to a brush body.
 16. The method of claim 15, wherein said securing step includes mechanically fastening the cover to the brush body.
 17. The method of claim 15, wherein said securing step comprises welding the cover to the brush body.
 18. The method of claim 15, wherein said securing step includes bonding the cover to the brush body with a adhesive.
 19. The method of claim 14, further comprising the step of imparting to the cover the shape of a brush body, at least subsequent to said separating step.
 20. Apparatus for making brushes from bristles, comprising at least one source of bristles; an assembling unit including at least one permeable form having bristle-receiving open-ended sockets; means for conveying predetermined numbers of bristles from said source to said sockets, including means for drawing air from said sockets through said form so that the bristles are introduced into the sockets by suction and portions of introduced bristles are located at the open ends of the respective sockets; and means for enlarging said portions of the bristles at the open ends of the respective sockets.
 21. The apparatus of claim 20 said bristles being made of thermoplastic material, wherein said enlarging means includes means for heating said portions of introduced bristles at least close to the melting point of the thermoplastic material of the bristles.
 22. The apparatus of claim 20, wherein said conveying means further comprises a conduit for each of said predetermined numbers of bristles, said conduits having receiving ends at said at least one source and discharge ends at the open ends of said sockets, said means for drawing air including means for advancing bristles by suction from the receiving ends toward and beyond the discharge ends of said conduits.
 23. The apparatus of claim 22, further comprising means for effecting a relative movement between the discharge ends of said conduits and said form.
 24. The apparatus of claim 22, wherein said at least one source includes means for maintaining said predetermined numbers of bristles in a first predetermined distribution and said receiving ends are in a distribution which matches said first distribution so that each of said receiving ends is in a position to receive one of said predetermined numbers of bristles, said sockets being in a second predetermined distribution and said discharge ends being in a distribution matching said second distribution so that each discharge end is in a position to admit one of said predetermined numbers of bristles into a discrete socket of said form.
 25. The apparatus of claim 22, wherein each of said conduits is flexible, at least in the region of at least one of said ends thereof.
 26. The apparatus of claim 25, wherein each of said conduits comprises a hose.
 27. The apparatus of claim 22, wherein said conveying means further comprises a carrier for the receiving ends of said conduits.
 28. The apparatus of claim 27, wherein said carrier has passages for said predetermined numbers of bristles and each of said passages communicates with and converges toward the receiving end of a discrete conduit.
 29. The apparatus of claim 28, wherein each of said passages has a minimum diameter which substantially equals the inner diameter of the respective conduit.
 30. The apparatus of claim 22, wherein said conveying means further comprises a support for the discharge ends of said conduits.
 31. The apparatus of claim 22, further comprising flow restrictors between said conduits and the respective sockets.
 32. The apparatus of claim 31, wherein each of said flow restrictors comprises or constitutes a venturi.
 33. The apparatus of claim 22, wherein said at least one source comprises a plurality of magazines and means for transferring predetermined numbers of bristles from said magazines to the receiving ends of said conduits.
 34. The apparatus of claim 22, wherein each of said conduits has an inner diameter in the range of 0.1 to 20 mm.
 35. The apparatus of claim 22, wherein said unit comprises a plurality of forms and further comprising means for transporting said plurality of forms in a predetermined direction along a predetermined path having a first portion adjacent said discharge ends and a second portion adjacent said enlarging means downstream of said first portion.
 36. The apparatus of claim 35, wherein said path has a third portion downstream of said second portion and further comprising a source of supply of brush bodies and means for delivering brush bodies from said source of supply to successive forms in the third portion of said path.
 37. The apparatus of claim 35, wherein said path has a third portion downstream of said second portion and further comprising means for treating the bristles in successive forms in said third portion of said path.
 38. The apparatus of claim 35, wherein said transporting means includes an endless conveyor having a first reach defining said first and second portions of said path and a second reach defining an additional portion of said path downstream of said second portion, and further comprising means segregating said predetermined numbers of bristles from the respective forms in the additional portion of said path.
 39. The apparatus of claim 22, wherein said form includes a main section and a cover overlapping said main section, said main section having blind holes constituting portions of said sockets and said cover having apertures constituting the open ends of said sockets, said portions of introduced bristles in said sockets being located at the respective apertures of said cover.
 40. The apparatus of claim 39, wherein said apertures include portions which are spaced apart from and diverge in a direction away from said main section.
 41. The apparatus of claim 39, wherein each of said apertures communicates with at least one other aperture of said cover.
 42. The apparatus of claim 20, wherein said at least one source comprises at least one magazine, and further comprising means for accumulating said predetermined numbers of bristles including at least one transfer member having bristle-receiving pockets and means for moving said transfer member between at least one first position in which at least some of said pockets receive bristles from said at least one magazine and at least one second position in which the bristle-containing pockets are located externally of said at least one magazine.
 43. The apparatus of claim 42, wherein said conveying means further comprises conduits, one for each of said sockets and each having a receiving end in register with a bristle-containing pocket in the second position of said at least on transfer member.
 44. The apparatus of claim 20, wherein said sockets are blind holes and said form has profiled bottom surfaces in said blind holes to intercept and arrest the introduced bristles in predetermined axial positions with reference to said form.
 45. The apparatus of claim 20, wherein said drawing means comprises at least one suction channel provided in said form for each of said sockets and extending substantially laterally of and communicating with the respective socket, and means for evacuating air from said channels.
 46. The apparatus of claim 45, wherein said evacuating means comprises a suction chamber, said channels having intake ends communicating with the respective sockets and discharge ends communicating with said chamber.
 47. The apparatus of claim 20, wherein said form includes at least one foraminous insert adjacent said sockets and said drawing means includes means for evacuating air from said sockets through said at least one insert.
 48. The apparatus of claim 47, wherein said evacuating means includes a suction chamber provided in said form adjacent said at least one insert.
 49. The apparatus of claim 20, wherein each of said sockets forms part of a discrete cylinder chamber provided in said form and said form further comprises a piston extending into each of said cylinder chambers and constituting an abutment for bristles which are introduced into the respective socket, said form further having means for moving said pistons in the respective cylinder chambers to thus vary the effective depth of said sockets and to select the positions of said portions of introduced bristles with reference to the open ends of the respective sockets.
 50. The apparatus of claim 20, wherein said form has bottom surfaces in said sockets, said bottom surfaces being remote from the open ends of the respective sockets and at least one of said bottom surfaces having at least one hill and at least one valley so that the bristles which are introduced into the socket adjacent said one bottom surface abut said hill or said valley and are thus staggered in the respective socket.
 51. The apparatus of claim 20, wherein said unit comprises at least two forms each of which has a plurality of sockets, said conveying means further comprising conduits defining discrete paths for simultaneous delivery of bristles from said source to the sockets of each of said forms.
 52. The apparatus of claim 20, wherein said conveying means further comprises means for receiving bristles from said at least one source, for gathering the thus received bristles into tufts containing different numbers of bristles and for delivering said tufts to said sockets.
 53. The apparatus of claim 20, wherein said at least one source comprises a plurality of magazines and means for simultaneously withdrawing tufts of bristles from said magazines.
 54. The apparatus of claim 53, wherein said magazines include a first and a second magazine and said withdrawing means comprises a transfer member disposed between said first and second magazines and having first and second sides adjacent said first and second magazines, each of said sides having at least one bristle-receiving pocket and further comprising means for moving said transfer member between at least one first position in which said pockets receive bristles from the respective magazines and at least one second position in which the bristle-containing pockets are spaced apart from said magazines.
 55. The apparatus of claim 20, wherein said form includes a main section and a cover overlapping and being separable from said main section, said sockets including portions in said main section and said cover having apertures constituting the open ends of said sockets, said cover having a flange surrounding a recess of a brush body.
 56. The apparatus of claim 55, wherein said cover consists of a material which is the material of the brush body, said cover being detachable from said main section together with the introduced bristles upon completed enlargement of said portions of inserted bristles.
 57. The apparatus of claim 20, wherein said form includes a main section and a cover which is detachable from the main section with the introduced bristles and constitutes a brush body.
 58. The apparatus of claim 20, wherein said conveying means further comprises means for mechanically advancing predetermined numbers of bristles from said source to said sockets.
 59. The apparatus of claim 58, wherein said advancing means comprises a transfer member and means for moving said transfer member between at least one first position in which said member receives predetermined numbers of bristles from said source and at least one second position in which the thus received bristles are aligned with the sockets of said form.
 60. The apparatus of claim 59, further comprising guide means having openings in register with the open ends of said sockets, at least in said at least one second position of said transfer member, and said guide means being disposed between said open ends and said transfer member in said at least one second position of said transfer member so that said drawing means can introduce bristles into said sockets through the openings of said guide means.
 61. The apparatus of claim 58, wherein said form has at least one foraminous insert adjacent said sockets and said drawing means includes means for evacuating air from said sockets through said at least one insert.
 62. The apparatus of claim 58, wherein said form includes a main section and a cover overlapping and being separable from said main section, said sockets having portions in said main section and said cover having apertures constituting the open ends of said sockets, said cover comprising thermoplastic projections adjacent said apertures and said enlarging means including means for bonding said portions of at least some introduced bristles to the adjacent projections of said cover.
 63. The apparatus of claim 20, wherein said at least one source comprises at least one magazine and further comprising an indexible transfer member having bristle-receiving pockets, and means for indexing said transfer member between at least one first position in which at least some of said pockets receive bristles from said at least one magazine and at least one second position in which the bristle-containing pockets are spaced apart from said at least one magazine.
 64. The apparatus of claim 63, wherein said at least one source comprises a plurality of magazines and said pockets form sets of pockets, said transfer member being indexible in a single direction between a plurality of first and second positions in each of which several sets of pockets receive bristles from said magazines and several sets of bristle-containing pockets are spaced apart from said magazines.
 65. The apparatus of claim 64, wherein said transfer member is indexible through angles of approximately 90°.
 66. The apparatus of claim 65, wherein said at least one source comprises two magazines which are located substantially diametrically opposite each other with reference to said transfer member.
 67. The apparatus of claim 63, wherein said transfer member has a peripheral surface and said pockets are open substantially axially parallel recesses in said peripheral surface.
 68. The apparatus of claim 63, wherein said transfer member is a rotary disc.
 69. The apparatus of claim 63, wherein the bristle-containing pockets register with said sockets in the at least one second position of said transfer member.
 70. The apparatus of claim 63, wherein said conveying means further comprises conduits which establish paths for advancement of bristles from bristle-containing pockets to said sockets in said at least one second position of said transfer member. 